THE   UNIVERSITY 

OF   ILLINOIS 

LIBRARY 


AGRICULTURAL 
LIBRARY 


>. 


UNIVERSITY  OF  ILLINOIS 

Agricultural  Experiment  Station 


BULLETIN  No.   209 


FERTILIZING  CONSTITUENTS  EXCRETED 
BY  TWO-YEAR-OLD  STEERS 


BY  H.  S.  GRINDLEY,  H.  W.  MUMFOED,  A.  D.  EMMETT, 
AND  SLEETER  BULL 


URBANA,  ILLINOIS,  JUNE,  1918 


CONTENTS  OF  BULLETIN  No.  209 

PAGE 

1.  THE  EXPERIMENT 129 

2.  AMOUNTS  AND  COMPOSITION  OF  FEEDS  CONSUMED 132 

3.  AMOUNTS  AND  COMPOSITION  OF  FECES 133 

4.  AMOUNTS  AND  COMPOSITION  OF  URINE 136 

5.  EXCRETION  OF  ORGANIC  MATTER 138 

6.  EXCRETION  OF  NITROGEN  , 143 

7.  EXCRETION  OF  PHOSPHORUS ..150 

8.  FINANCIAL  STATEMENT  .  .  .  155 

9.  SUMMARY 159 

10.  CONCLUSIONS.,                                                                                           .  .101 


FERTILIZING  CONSTITUENTS  EXCRETED 
BY  TWO-YEAR-OLD  STEERS 

BY  H.  S.  GKINDLEY,  H.  W.  MUMFORD,  A.  D.  EMMETT, 
AND  SLEETER  BULL1 

This  bulletin  is  one  of  a  series2  reporting  the  findings  of  an  inves- 
tigation in  regard  to  the  effect  of  variations  in  the  character  and 
amount  of  feed  consumed  upon  the  nutrition  of  steers.  It  gives  the 
results  relating  to  the  fertilizing  constituents  of  the  excreta,  includ- 
ing (1)  the  amounts  of  nitrogen,  phosphorus,  and  organic  matter  ex- 
creted, (2)  the  manner  of  excretion,  i.  e.,  whether  via  the  feces  or  the 
urine,  and  (3)  the  commercial  value  of  the  fertilizing  elements  of  the 
excreta. 

Inasmuch  as  no  bedding  was  used  in  this  experiment,  its  fertiliz- 
ing value  is  not  considered  in  the  general  discussion  of  the  results. 
It  should  be  borne  in  mind,  however,  that  ordinary  bedding,  such  as 
straw,  does  contain  considerable  fertilizing  value  which  should  be 
added  to  the  commercial  value  of  the  excreta  proper.  For  a  discussion 
of  the  manurial  value  of  bedding  the  reader  is  referred  to  other 
sources.3 

THE  EXPERIMENT 

The  Animals. — The  animals  used  were  eight  two-year-old  high- 
grade  Hereford  steers,  grading  as  choice  feeders  and  weighing  from 
800  to  1,000  pounds.  These  animals  were  selected  from  the  same  herd. 
From  birth  to  the  time  of  purchase  they  had  been  treated  very  much 
alike.  During  a  period  of  about  two  months  preliminary  to  the  ex- 
periment they  were  kept  in  paved  lots  with  access  to  open  sheds,  and 
during  the  experiment  proper,  which  lasted  from  May  27,  1908,  to 
February  10,  1909,  a  period  of  thirty-seven  weeks,  they  were  kept  in 
digestion  and  metabolism  stalls. 

Rations  and  Feeds. — During  the  first  month  of  the  period  prelim- 
inary to  the  experiment  the  ration  consisted  of  corn  silage,  clover  hay, 
and  alfalfa  hay.  At  the  beginning  of  the  second  month  ground  corn 
was  added  to  the  ration,  and  the  feeding  of  alfalfa  was  discontinued. 
Four  days  later  the  feeding  of  corn  silage  was  discontinued. 


"The  authors  take  pleasure  in  acknowledging  their  great  indebtedness  to  Pro- 
fessors L.  D.  Hall  and  H.  O.  Allison  for  their  generous  and  helpful  cooperation 
and  assistance  in  the  planning  and  conducting  of  this  investigation. 

"See  111.  Agr.  Exp.  Sta.  Buls.  172  and  197. 

'Hopkins:  Soil  Fertility  and  Permanent  Agriculture,  p.  541,  et  seq.  Van 
Slyke:  Fertilizers  and  Crops,  p.  301,  et  seq. 

129 


130  BULLETIN   No.  209  [Jitnr, 

During  the  first  twenty-two  weeks  of  the  experiment  proper  the  ration 
consisted  of  clover  hay  and  ground  corn,  and  during  the  last  fifteen 
weeks,  of  clover  hay,  ground  corn,  and  linseed  oil  meal.  Half  an  ounce 
of  salt,  given  daily,  was  taken  very  consistently  by  all  of  the  steers. 
Water  also  was  given  twice  daily,  and  an  exact  record  was  kept  of  the 
amounts  drunk. 

To  determine  the  effect  of  variations  in  the  proportions  of  rough- 
age to  concentrates  in  the  ration,  and  the  effect  of  the  introduction  of 
linseed  oil  meal  into  the  ration,  the  experiment  was  divided  into  five 
experimental  periods.  During  the  first  experimental  period  the  ration 
consisted  of  clover  hay  and  ground  corn  in  equal  amounts  by  weight ; 
during  the  second,  of  one  part  of  clover  hay  and  three  parts  of  ground 
corn;  during  the  third,  of  one  part  of  clover  hay  and  five  parts  of 
ground  corn ;  and  during  the  fourth  and  fifth,  of  one  part  of  clover 
hay,  four  parts  of  ground  corn,  and  one  part  of  linseed  oil  meal.  Thus 
the  proportion  of  concentrates  was  gradually  increased  up  to  the 
third  experimental  period,  and  then  maintained  constant  to  the  end 
of  the  experiment.  These  changes  are  comparable  to  the  changes 
often  made  in  the  proportions  of  roughage  and  concentrates  in  ordi- 
nary feeding  practice.  The  first  experimental  period  was  five  weeks 
in  length;  the  second,  third,  and  fourth,  each  six  weeks  in  length; 
and  the  fifth,  four  weeks  in  length.  The  changes  in  the  ration  made 
from  one  test  period  to  another  were  effected  very  gradually  in  trans- 
itional periods  one  of  which  immediately  followed  each  experimental 
period.  The  first  and  third  transitional  periods  were  two  weeks  in 
length ;  and  the  second  and  fourth,  three  weeks  in  length. 

TABLE  1. — DIVISION  OP  EXPERIMENT  INTO  PERIODS,  AND  RATIOS  OF  HAY,  CORN 
AND  LINSEED  MEAL  IN  RATIONS 


Experimental 
period 

Experimental 
weeks 

Number  of  weeks 
in  period 

Ratio  of  hay  to  corn 
to  linseed  meal 

1 

2 
3 
4 
5 

1-5 
8-13 
17-22 
25-30 
34-37 

5 
6 
6 
6 
4 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

To  determine  the  effect  of  variations  in  the  amount  of  feed  con- 
sumed, the  eight  steers  were  divided  into  four  lots  of  two  animals  each, 
and  each  lot  was  given  thruout  the  experiment  an  amount  of  feed 
different  from  that  received  by  the  other  lots.  The  lots  were  as  similar 
as  possible  in  regard  to  age,  condition,  and  breeding.  One  lot  was 
given  just  enough  feed  to  maintain  the  weights  of  the  steers  about 
constant ;  another,  as  much  as  the  steers  would  eat  readily ;  another,  an 
amount  of  feed  equal  to  the  maintenance  ration  plus  one-third  of  the 
difference  between  the  maintenance  and  the  full-feed  rations;  and 
another,  an  amount  equal  to  the  maintenance  ration  plus  two-thirds 


1918]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS  131 

of  the  difference  between  the  maintenance  and  full-feed  rations.  Be- 
ginning with  the  31st  week,  one  steer  each  from  the  maintenance,  the 
one-third,  and  the  two-thirds  feed  lots  was  gradually  put  on  a  full-feed 
ration  and  continued  thus  until  the  end  of  the  experiment. 

The  average  daily  gains  of  the  different  lots  during  the  thirty- 
seven  weeks  of  the  experiment  were  as  follows :  maintenance  lot,  0.76 
pound;  one-third-feed  lot,  1.28  pounds;  two-thirds-feed  lot,  1.76 
pounds ;  and  full-feed  lot,  2.05  pounds. 

Equipment  and  Methods. — For  a  detailed  description  of  the 
equipment  and  methods  used  in  this  investigation,  see  Bulletin  172  of 
this  station.  In  this  connection,  it  will  be  sufficient  to  state  briefly  the 
essentials  of  the  procedure.  The  feeds  were  thorbly  mixed,  analyzed, 
and  weighed  out  to  each  steer.  The  refused  feeds,  or  orts,  were  also 
weighed,  mixed,  and  analyzed.  From  the  data  so  obtained,  the  quantir 
ties  of  organic  matter,  nitrogen,  and  phosphorus  consumed  by  each 
steer  were  calculated.  The  feces  were  weighed,  mixed,  and  analyzed, 
and  the  quantities  of  organic  matter,  nitrogen,  and  phosphorus  ex- 
creted via  the  intestines  were  calculated.  The  urine  was  weighed, 
mixed,  and  analyzed,  and  the  quantities  of  nitrogen  and  phosphorus 
excreted  thru  the  kidneys  were  calculated.  The  details  of  the  methods 
used  in  the  collection  and  sampling  of  the  urine  are  given  below  since 
they  were  not  reported  in  Bulletin  172. 

Collection  and  Sampling  of  Urine. — The  weighing  of  the  urine 
was  done  at  the  end  of  the  experimental  day.  After  the  total  weight 
of  this  twenty-four  hour  sample  was  obtained,  the  urine  was  stirred 
thoroly  and  one-fourth  of  the  total  amount  was  weighed  off  for  the 
daily  sample.  The  urine  sample  was  transferred  to  a  dry,  thymolized 
bottle,  provided  with  a  cork  stopper.  The  acidity  or  alkalinity  of  the 
urine  to  litmus  was  ascertained  at  the  time  of  the  sampling  each  day. 
The  samples  of  urine  and  feces  were  taken  to  cold  storage  rooms 
and  kept  until  the  end  of  the  experimental  week. 

The  samples  of  the  urine  were  composited  weekly.  In  doing 
this,  the  seven  daily  fractions  for  each  steer  were  transferred  to  a 
large  pail  and  stirred  thoroly  until  well  mixed.  Then  two  liters  of 
the  composite  sample  was  strained  thru  a  40-mesh  sieve  into  a  thymo- 
lized bottle.  In  this  way  hair  or  foreign  matter  that  might  be  present 
was  removed,  but  the  normal  sediment  passed  thru.  The  alkalinity  or 
acidity  of  the  composite  samples,  the  color  of  the  urines,  the  compar- 
ative amount  of  sediment,  and  the  specific  gravity,  with  the  temper- 
ature, were  all  recorded.  The  samples  were  then  ready  for  chemical 
examination. 

Methods  of  Analysis. — The  methods  of  analysis  used  in  this  ex- 
periment were  essentially  the  same  as  the  official  methods  given  in  the 
revised  edition  for  1908  of  Bulletin  107  of  the  Bureau  of  Chemistry, 
United  States  Department  of  Agriculture.  The  total  carbohydrates 
were  determined  by  difference.  No  determinations  were  made  of  the 
crude  fiber. 


132 


BULLETIN   No.  209 


f  June, 


The  total  amounts  of  feeds  consumed  by  each  animal  per  period 
are  given  in  Table  2;  the  average  amounts  of  feeds  consumed  daily 
per  steer  per  period  are  given  in  Table  3;  and  Table  4  shows  the 
average  chemical  composition  of  the  feeds.  For  a  more  complete  dis- 
cussion of  the  feed  consumption  and  composition,  the  reader  is  re- 
ferred to  Bulletin  197  of  this  station. 


TABLE  2. — TOTAL  FEED  CONSUMED  PER  PERIOD 
(Results  expressed  in  pounds) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Clover 
hay 

Ground 
corn 

Linseed 
meal 

Clover 
hay 

Ground 
corn 

Linseed 
meal 

Maintenance  Lot 

1 
2 
3 

4 
53 

Total* 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  650 

Steer  656 

192.6 
95.8 
58.8 
58.2 
81.7 

627.4 

192.6 
287.3 
294.0 
233.0 
326.9 

1791.6 

58~2 
81.7 

184.7 

192.6 
95.6 
58.8 
58.2 
37.0 

577.4 

192.6 
286.8 
294.0 
233.0 
147.8 

1589.5 

58  '.2 
37.0 

133.3 

One-Third-Feed  Lot 

1 
2 
3 
4 
53 

Total4 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

270.0 
153.4 
88  5 
84.0 
88.6 

890.7 

270.0 
460.3 
442  .4 
336.0 
354.4 

2537.3 

84^6 
88.6 

236.3 

277.9 
160.0 
96.0 
90.7 
60.5 

901.8 

277.9 
479.8 
480.2 
362.9 
241.9 

2549.9 

66!  7 
60.5 

214.3 

Two-Thirds-Feed  Lot 

1 
2 
3 
4 

5:! 

Total4 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6521 

Steer  665 

348.9 
210.1 
119.3 
109.8 
21.5 

1079.6 

348.9 
630.4 
596.4 
439.0 
86.1 

2981.3 

109'  8 
21.5 

211.1 

362.8 
224.7 
134.4 
123.2 
84.0 

1221.7 

362.8 
674.3 
672.0 
492.8 
336.0 

3503  1 

12S!  2 
84.0 

294.4 

Full-Feed  Lot 

1 
2 
3 
4 
5 

Total4 

1-5 
8   11 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  663'2 

Steer  661 

408.4 
241.3 
128.5 
118.2 

408.4 
723.9 
642.6 
472.8 

444.1 

283.6 
144.8 
155.7 
105.2 

1496.6 

444.1 
851.0 
724.2 
622.7 
420.8 

4252.3 

17-22 
25-30 
34-37 

1-37 

118.2 

155.7 
105.2 

372.3 

1144.1 

3002  .2 

145.2 

'Removed  at  end  of  34th  week.    'Removed  at  end  of  30th  week. 
"Steers  650,  666,  and  652  were  on  full  feed  in  this  period, 
includes  feeds  for  transitional  periods. 


1918]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS 


133 


TABLE  3. — AVERAGE  FEED  CONSUMED  DAILY 
(Results  expressed  in  pounds) 


Pe- 
riod 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Clover 
hay 

Ground 
corn 

Linseed 
meal 

Clover 
hay 

Ground 
corn 

Linseed 
meal 

Maintenance  Lot 

1 
2 
3 

4 
53 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  650 

Steer  656 

5.50 
2.28 
1.40 
1.39 
2.92 

5.50 
6.84 
7.00 
5.55 
11.67 

i!39 
2.92 

5.50 
2.28 
1.40 
1.39 
1.32 

5.50 
6.83 
7.00 
5.55 
5.28 

i^39 
1.32 

One-Third-Feed  Lot 

1 
2 
3 
4 
53 

1-5 
•   8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

7.71 
3.65 
2.11 
2.00 
3.16 

7.71 
10.96 
10.53 
8.00 
12.66 

2^66 
3.16 

7.94 
3.81 
2.29 
2.16 
2.16 

7.94 
11.42 
11.43 
8.64 
8.64 

2.16 
2.16 

Two-Thirds-Feed  Lot 

1 
2 
3 
4 
53 

1-5 
18-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6521 

Steer  665 

9.97 
5.00 
2.84 
2.61 
3.07 

9.97 
15.01 
14.20 
10.45 
12.29 

2.61 
3.07 

10.37 
5.35 
3.20 
2.93 
3.00 

10.37 
16.06 
16.00 
11.73 
12.00 

2  '93 
3  00 

Full-Feed  Lot 

1 
2 
3 
4 
fi 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  663* 

Steer  661 

11.67 
5.75 
3.06 
2.81 

11.67 
17.24 
15.30 
11.26 

2'si 

12.69 
6.75 
3.45 
3.71 
3.76 

12.69 
20.26 
17.24 
14.83 
15.03 

3.71 

3.76 

'Removed  at  end  of  34th  week.     -'Removed  at  end  of  30th  week. 
"Steers  650,  666,  aud  652  were  on  full  feed  in  this  period. 

TABLE  4. — AVERAGE  COMPOSITION  OF  FEEDS 
(Results  expressed  in  percent  of  fresh  substance) 


Feed 

Dry 

sub- 
stance 

Or- 
ganic 
matter 

Crude 
protein 
(Nx 
6.25) 

Total 
car- 
bohy- 
drates 

Fat 
(ether 
ex- 
tract) 

Ash 

Total 
nitro- 
gen 

Phos- 
phorus 

Ground  corn  .  . 
Linseed  meal.  . 
Clover  hay.  .  .  . 

87.09 
90.74 
88.46 

85.82 
85.32 
83.07 

7.69 
34.80 
10.97 

74.21 
43.72 
69.75 

3.93 
6.79 
2.36 

1.27 
5.42 
5.39 

1.230 
5.564 
1.756 

0.263 
0.869 
0.153 

AMOUNTS  AND  COMPOSITION  OF  FECES 

As  would  be  expected,  the  amounts  of  feces  excreted  depended 
roughly  upon  the  amount  of  the  ration  consumed  and  upon  the  pro- 
portion of  roughage  in  the  ration  (see  Tables  5  and  6).  However, 
there  was  considerable  variation  in  the  amounts  excreted  by  the  steers 
of  the  same  lot  in  the  same  period. 


134 


BULLETIN   No.   209 


TABLE  5. — TOTAL  FECES  EXCRETED  PER  PERIOD 
(Results  expressed  in  pounds) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance  Lot 

One-Third-Feed  Lot 

Steer 
650 

Steer 
656 

Steer 
666 

Steer 
669 

1 
2 
3 

4 
5- 

Total4 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

721.45 
457.02 
344.52 
284.40 
555.36 

3066  .  19 

623  .  25 
468.78 
372.36 
336.96 
227.14 

2713.39 

966.05 
848  .  28 
559.32 
515.76 
757.37 

4868  .  95 

1284.15 
927.66 
644.04 
581.40 
373.49 

5155.09 

Two-Thirds-Feed  Lot 

Full-Feed  Lot 

1 
2 
3 
4 
55 

Total4 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer 
6521 

Steer 
665 

Steer 
6633 

Steer 
661 

1599.95 
1306.38 
823  .  02 
802  .  32 
155.17 

6473.49 

1583.45 
1448.76 
1063  .  92 
872  .  88 
603  .  78 

7545.01 

1824.25* 
1469.16 
918.66 
698.82 

2156.25 
2240.64 
1323.24 
1177.74 
802.05 

10538.34 

6469.69 

'Removed  at  end  of  34th  week.    "Removed  at  end  of  30th  week. 
"Weeks  3,  4,  and  5  only.    ^Includes  transitional  periods. 
6Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 


TABLE  6. — AVERAGE  FECES  EXCRETED  PER  WEEK 
(Results  expressed  in  pounds) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance  Lot 

One-Third-Feed  Lot 

Steer 
650 

Steer 
656 

Steer 
666 

Steer 
669 

•    1 

2   . 
3 
4 
5* 
Aver- 
age4 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

144.29 
76.17 
57.42 
47.40 
138.84 

82.87 

124.65 
78.13 
62.06 
60.66 
56.78 

73.33 

193.21 
141.38 
93.22 
85.96 
189.34 

131.59 

256.83 
154.61 
107.34 
96.90 
93.37 

139.33 

Two-Thirds-Feed  Lot 

Full-Feed  Lot 

1 
2 
3 
4 
B» 
Aver- 
age4 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0    . 
1:5:0 
1:4:1 
1:4:1 

Steer 
652' 

Steer 
665 

Steer 
6632 

Steer 
661 

319.99 
217.73 
137.17 
133.72 
155.  17 

190.40 

316.69 
241.46 
177.32 
145.48 
150.94 

203.92 

364.85" 

244.86 
153.11 
116.47 

431.25 
373.44 
220.54 
196.29 
200.51 

284.82 

231.0 

'Removed  at  end  of  34th  week.    ^Removed  at  end  of  30th  week. 
"Weeks  3,  4,  and  5  only.    ^Includes  transitional  periods. 
5Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 


l'JLS\       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS          135 


With  respect  to  the  percentages  of  water  and  organic  matter 
in  the  feces,  the  individual  steers  of  the  different  lots  were  quite  sim- 
ilar in  the  same  period  (see  Table  7).  In  the  cases  of  nitrogen  and 
phosphorus,  the  variations  of  the  different  steers  in  the  same  period 
were  greater. 

TABLE  7. — CHEMICAL  COMPOSITION  OF  FECES 
(Results  expressed  in  percent  of  fresh  substance) 


Pe- 
riod 

Weeks 

Ratio  of 
hay  to 
corn  to 

linseed 
meal 

Water 

Or- 
ganic 
matter 

Ni- 
trogen 

Phos- 
phor- 
us 

Water 

Or- 
ganic 
matter 

Ni- 
trogen 

Phos- 
phor- 
us 

Maintenance  Lot 

1 
2 
3 
4 
53 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  650 

Steer  656 

85.32 
83.14 
80.53 
78.66 
80.78 

13.42 
15.40 
17.85 
19.20 
17.65 

0.478 
0.586 
0.643 
0.755 
0.605 

0.110 
0.189 
0.232 
0.339 
0.238 

83.82 
84.77 
82.52 
82.11 
82.61 

14.87 
14  .  08 
16.31 
16.63 
15.81 

0.488 
0.537 
0.596 
0.620 
0.633 

0.101 
0.101 
0.088 
0.098 
0.100 

One-Third  Feed  Lot 


1 

2 
3 

4 
53 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

84.66 
82.75 
79.17 
80.77 
84.13 

14.10 
15.82 
19.28 
17.47 
14.44 

0.458 
0.476 
0.585 
0.676 
0.533 

0.101 
0.157 
0.213 
0.265 
0.217 

86.12 
82.68 
81.51 
80.26 
81.47 

12.76 
16.01 
16.94 
17.94 
16.81 

0.384 
0.434 
0.537 
0.630 
0.585 

0.088 
0.142 
0.209 
0.294 
0.281 

Two-Thirds-Feed  Lot 


1 

2 
3 
4 
53 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6521 

Steer  665 

86.32 
82.85 
81.90 
83.76 

83.85 

12.58 
15.88 
16.85 
14.92 
15.21 

0.405 
6.450 
0.573 
0.571 
0.540 

0.099 
0.136 
0.155 
0.177 
0.215 

85.39 
81.59 
80.69 
79.47 
80.69 

13.52 
17.13 
17.93 
18.92 
17.72 

0.423 
0.445 
0.491 
0.606 
0.582 

0.098 
0.146 
0.180 
0.254 
0.240 

Full-Feed  Lot 


1 

2 
3 
4 
5 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6632 

Steer  661 

85.61 

82.37 
80.78 
81.39 

13  .  33 
16.27 
17.91 
16.77 

0.412 
0.486 
0.530 
0.611 

0.096 
0.145 
0.148 

0.287 

86.05 
82.29 
79.83 
81.12 
83.18 

12.87 
16.56 
18.85 
17.45 
15.39 

0.397 
0.398 
0.448 
0.571 
0.537 

0.093 
0.119 
0.148 
0.207 
0.220 

'Removed  at  end  of  34th  week.    2Bemoved  at  end  of  3.0th  week. 
"Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 


136 


Hl'LLKTlN     Xo.     2( 


TABLE  8. — AVERAGE  CHEMICAL  COMPOSITION  OF  FECKS 
(Results  expressed  in  percent  of  fresh  substance) 


Ratio  of 

Period 

Weeks 

hay  to 
corn  to 
linseed 

Water 

Organic 
matter 

Nitrogen 

Phosphorus 

meal 

1 

1-5 

1:1:0 

85.41 

13.43 

0.431 

0.098 

2 

8-13 

1:3:0 

82.80 

15.89 

0.476 

0.142. 

3 

17-22 

1:5:0 

80.87 

17.74 

0.550 

0.172 

4 

25-30 

1:4:1 

80.94 

17.41 

0.630 

0.240 

5 

34-37 

1:4:1 

82.39 

16.15 

0.574 

0.216 

AMOUNTS  AND  COMPOSITION  OF  URINE 

The  weights  of  the  urine  excreted  and  the  percentages  of  total 
nitrogen  and  phosphorus  in  the  urine  are  given  in  Tables  9  to  12, 
inclusive.  In  the  case  of  the  phosphorus  determination,  the  results 
obtained  were  none  too  satisfactory ;  which  fact,  along  with  the  pres- 
sure of  other  duties,  caused  this  work  to  be  abandoned  after  the 
thirteenth  week.  The  results,  so  far  as  determined,  are  given  in  Table 
12.  While  not  accurate,  these  results  serve  as  an  indication  of  the 
amounts  of  phosphorus  present  in  the  urine.  The  excretion  of  phos- 
phorus in  the  urine  was  very  small  except  in  case  of  Steer  656,  whose 
urine  contained  much  more  phosphorus  than  the  urine  of  the  other 
steers.  Further  mention  is  made  of  this  fact  later  in  the  discussion. 

TABLE  9. — TOTAL  URINE  EXCRETED  PER  PERIOD 
(Results  expressed  in  pounds) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance  Lot 

One-Thifd-Feed  Lot 

Steer 
650 

Steer 
656 

Steer 
666 

Steer 
669 

1 
2 
3 

4 
54 

Total3 

1-5 

8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

209.60 
295  .  86 
212.46 
•     262.80 
207.27 

1575.15 

419.35 
612.12 
260.70 
292.50 
172.66 

2366  .  48 

247  .  05 
361.32 
313.68 
283.14 
258.25 

1977.19 

310.05 
658.74 
508.20 
311.58 
201.64 

2782.09 

Two-Thirds-Feed  Lot 

Full-Feed  Lot 

1 
2 
3 
4 
6* 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer 
6521 

Steer 
665 

Steer 
663* 

Steer 
661 

375.80 
567.24 
730.68 
588.66 
97.31 

3337.42 

327.45 
323.82 
315.60 
481.44 
330.81 

2428.27 

400.70 
501.84 
255  .  72 
522.30 

438.70 
604.86 
412  .  62 
680.10 
419.13 

3422.98 

2237.62 

'Bemoved  at  end  of  34th  week.     2Bemoved  at  end  of  3.0th  week. 

"Includes  transitional  periods. 

4Steers  650,  666,  and  652  were  on  full  feed  iu  this  period. 


1918}       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS 


137 


TABLE  10. — AVERAGE  URINE  EXCRETED  PER  WEEK 
(Results  expressed  in  pounds) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance  Lot 

One-Third-Feed  Lot 

Steer 
650 

Steer 
656 

Steer 
666 

Steer 
669 

1 

2 
3 
4 
fr 
Aver- 
age8 

1-5 

8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

41.92 
49.31 
35.41 
43.80 
51.82 

42.57 

83.87 
102.02 
43.45 
48.75 
43.16 

63.96 

49.41 
60.22 
52.28 
47.19 
64.56 

53.44 

62.01 
109.79 
84.70 
51.93 
50.41 

75.19 

Two-Thirds-Feed  Lot 

Full-Feed  Lot 

1 

2 
3 
4 
54 
Aver- 
age3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer 
6521 

Steer 
665. 

Steer 
6632 

Steer 
661 

75.16 
94.54 
121  .  78 
98.11 
97.31 

98.16 

65.49 
53.97 
52.60 
80.24 

82.70 

65.63 

80..  14 
83.64 
42.62 
87.05 

87.74 
100.81 
68.77 
113.35 
104.78 

92.51 

74.59 

'Removed  at  end  of  34th  week.    ^Removed  at  end  of  30th  week. 

includes  transitional  periods. 

*Ste.ers  650,  666.  and  652  were  on  full  feed  in  this  period. 


TABLE  11.— TOTAL  NITROGEN  IN  URINE  PER  PERIOD 
(Expressed  in  percent  of  fresh  urine) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance  Lot 

One-Third-Feed  Lot 

Steer 
650 

Steer 
656 

Steer 
666 

Steer 
669 

1 

2 
3 
4 
53 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

0.788 
0.774 
0.717 
1.612 
2.389 

0.476 
0.351 
0.608 
1.557 
1.815 

0.886 
0.963 
1.015 
2.019 
2.473 

0.806 
0.524 
0.502 
2.190 
2.412 

Two-Thirds-Feed  Lot 

Full-Feed  Lot 

1 
2 
3 
4 
53 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer 
6521 

Steer 
665 

Steer 
663*      • 

.    Steer 
661 

0.730 
0.707 
0.416 
1.283 
1.729 

0.847 
1.266 
1.282 
1.774 
1  .  968 

0.745 
0.937 
1.379 

1.855 

0.735 
0.820 
0.965 
1.507 
1.893 

'Removed  at.  end  of  34th  week.  "Removed  at  end  of  30th  work. 
"Steers  650,  66fi,  and  652  were  on  full  feed  in  this  period. 


138 


BULLETIN   No.  209 


[June, 


TABLE  12. — TOTAL  PHOSPHORUS  IN  URINE  PER  PERIOD 
(Results  expressed  in  percent  of  fresh  urine) 


Pe- 
riod 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance 
Lot 

One-Third- 
Feed  Lot 

Two-Thirds- 
Feed  Lot 

Full-Feed 
Lot 

Steer 
650 

Steer 
656 

Steer 
666 

Steer 
669 

Steer 
652 

Steer 
665 

Steer 
663 

Steer 
661 
0.0031 
0.0035 

1 
2 

1-5 
8-13 

1:1:0 
1:3:0 

0.0030 
0.0034 

0.0302 
0.0472 

0.0034 
0.0036 

0.0028 
0.0023 

0.0026 
0.0026 

0.0029 
0.0038 

0.0025 
0.0030 

EXCRETION  OF  ORGANIC  MATTER 

The  proportion  of  the  organic  matter  of  the  ration  which  may  be 
recovered  in  the  manure  is  of  especial  importance  to  the  live-stock 
farmer  who  is  attempting  to  establish  a  permanent  system  of  soil  fer- 
tility. Decomposing  or  decomposed  organic  matter  in  the  soil  not 
only  acts  as  a  source  of  plant  food,  but  it  also  helps  to  make  available 
some  of  the  insoluble  mineral  plant  food,  (e.  g.,  raw  rock  phosphate). 
Also,  the  presence  of  organic  matter  favorably  influences  the  physical 
condition  of  the  soil. 

An  inspection  of  the  data  given  in  Tables  13  and  14  shows  that, 
in  general,  the  steers  on  the  larger  rations  excreted  a  larger  propor- 
tion of  organic  matter  than  the  steers  on  the  smaller  rations.  This 
was  undoubtedly  due  to  the  fact  that  the  digestibility  of  the  dry  sub- 
stance and  carbohydrates  in  Period  1,  when  the  ration  was  composed  of 
corn  and  clover  hay  in  equal  parts,  varied  inversely  as  the  amounts 
of  feeds  consumed.  Also  in  Period  2  there  was  an  indication  that 
the  digestibility  of  the  dry  substance -and  carbohydrates  varied  in- 
versely with  the  amounts  of  feeds  consumed.1  However,  the  differ- 
ences in  the  percentages  of  organic  matter  excreted  by  the  steers  of  the 
different  lots  during  the  same  period  were  small  and  it  seems  justifi- 
able to  take  an  average  of  them.  Such  averages  are  shown  in  Table 
27. 

The  percentage  of  organic  matter  excreted  varied  directly  with 
the  proportion  of  roughage  in  the  ration,  owing  to  the  fact  that  the 
digestibility  of  the  nutrients  of  the  ration  increased  as  the  ratio  of 
roughage  to  concentrates  was  varied  from  1  to  1  to  1  to  5.  From 
these  results  the  following  summary,  relating  to  the  percentage  of 
organic  matter  recovered  in  the  manure,  can  be  made :  In  Period 
1,  an  average  of  33  percent  of  the  organic  matter  consumed  was  re- 
covered in  the  feces;  in  Period  2,  28  percent;  in  Period  3,  24  percent; 
in  Period  4,  22  percent ;  in  Period  5,  23  percent ;  and  for  the  entire 
thirty-seven  weeks  of  the  experiment,  26  percent. 

'111.  Agr.  Exp.  Sta.  Bnl.  172. 


l'JL8\       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS          139 

From  the  data  given  in  Table  15,  it  is  apparent  that  in  Periods 
4  and  5  the  amount  of  feed  consumed  had  little  influence  upon  the 
percentage  of  organic  matter  excreted.  The  data  show  further  that 
when,  clover  hay,  ground  corn,  and  linseed  meal  were  fed  in  the  pro- 
portions of  1  to  4  to  1,  there  was  excreted  in  the  manure  from  22  to  31 
percent  (or  an  average  of  27  percent)  as  much  organic  matter  as 
was  consumed  in  the  farm-grown  feeds. 

In  the  case  of  the  organic  matter,  the  plant  elaborates  practically 
its  entire  content  from  the  carbon  dioxid  of  the  air  and  of  the  water 
and  other  inorganic  constituents  of  the  soil,  probably  not  drawing 
upon  the  organic  matter  of  the  soil  to  any  appreciable  extent.  How- 
ever, coincident  with  the  elaboration  of  organic  matter  by  the  plant 
from  the  air  and  water,  the  organic  matter  of  the  soil  is  being  broken 
down  by  natural  agencies,  such  as  the  various  chemical  and  biological 
actions  which  are  taking  place  in  the  soil.  That  is,  the  organic  matter 
of  the  soil  is  continuously  being  depleted,  and  this  depletion  appar- 
ently takes  place  whether  the  soil  is  fallow  or  producing  a  crop. 

When  farm  products  are  fed  to  live  stock  on  the  farm  rather  than 
sold  away  from  the  farm,  about  one-fourth  of  the  organic  matter  built 
up  by  the  plant  from  the  carbon  dioxid  of  the  air  and  the  water  and 
other  inorganic  constituents  of  the  soil  can  be  returned  to  the  soil  in 
some  organic  form,  and  the  organic  matter  applied  in  the  form  of 
manure  may  therefore  be  looked  upon  as  clear  gain  over  a  system 
of  farming  in  which  all  the  products  of  the  soil  are  sold  directly 
from  the  farm.  If  one  assumes  that  a  considerable  part  of  the 
stover,  straw,  etc.,  is  also  returned  to  the  soil,  as  is  usually  the 
case  in  live-stock  farming,  the  proportion  of  the  organic  matter 
of  the  crop  which  can  be  returned  to  the  soil  may  be  increased  to 
as  much  as  one-half  or  two-thirds.  The  results  of  this  experiment, 
as  well  as  actual  good  farming  practice,  indicate  that  the  destruction 
of  organic  matter  is  not  a  serious  proposition  in  live-stock  farming. 

It  is  also  of  interest  to  compare  the  amount  of  organic  matter 
returned  to  the  farm  when  the  corn  and  clover  are  fed  to  two-year-old 
beef  cattle,  with  the  amount  returned  by  a  system  of  farming  where 
the  corn  is  sold  and  the  clover  is  turned  under  as  a  green  manure. 
Referring  again  to  Table  14,  it  is  seen  in  the  case  of  the  maintenance 
lot,  that  in  all  periods  except  Periods  1  and  2  more  organic  matter 
could  have  been  returned  to  the  soil  by  feeding  the  corn  and  clover 
than  would  have  been  returned  to  the  soil  if  the  corn  had  been  sold 
and  the  clover  turned  under  as  green  manure.  An  average  of  the 
results  for  the  eight  steers  shows  that  in  Period  1,  68.16  percent  as 
much  organic  matter  was  recovered  in  the  manure  as  was  consumed  in 
the  clover  hay;  in  Period  2,  113.96  percent;  in  Period  3,  146.80  per- 
cent; in  Period  4,  136.38  percent;  and  in  Period  5,  137.11  percent. 


140  BULLETIN   No.   209  [June, 

Jn  I  ho  entiro  expovilnient  there  was  108.18  percent  as  much  organic 
matter  in  the  manure  as  would  have  been  returned  to  the  farm  by 
plowing  under  the  clover  and  selling  off  the  corn. 

In  this  connection  it  may  be  noted  that  in  good  rotations  in  the 
corn  belt  where  two  crops  of  corn  are  secured  in  a  four-  or  five-year 
rotation  (e.  g.,  corn,  corn,  oats,  and  clover;  or  corn,  corn,  oats,  clover, 
and  wheat),  corn  and  clover  hay  are  produced  in  approximately  the 
ratio  of  1.5  to  2  parts  of  corn  by  weight,  to  1  part  of  clover  hay — a 
ratio  not  greatly  different  from  the  proportions  in  which  these  feeds 
were  used  in  Periods  1  and  2.  In  a  three-year  rotation  (c.  g.,  corn, 
oats,  and  clover),  corn  and  clover  are  produced  in  about  equal 
amounts,  or  in  the  same  proportions  as  these  feeds  were  used  in  Period 
1.  Thus  it  is  seen  that  in  cither  the  four-  or  five-year  rotation  noted 
above,  as  much  or  more  organic  matter  could  be  returned  to  the  soil 
by  feeding  the  corn  and  clover  as  would  be  returned  if  the  com  were 
sold  and  the  clover  turned  under.  In  the  three-year  rotation  noted 
above,  about  two-thirds  as  much  organic  matter  could  be  returned  by 
feeding  tho  corn  and  clover  as  by  selling  the  corn  and  plowing  under 
the  clover. 

Of  course  the  results  of  Periods  3,  "4,  and  5  are  of  little  practical 
value  in  this  connection,  unless  the  feeder  purchases  corn  in  addition 
to  the  amount  produced  on  the  farm  or  feeds  a  part  of  his  clover  hay 
to  other  farm  animals.  Purchased  feeds  may  add  to  the  organic  mat- 
ter, but  only  at  the  expense  of  the  fertility  of  some  other  farm.  Con- 
sequently organic  matter  may  be  added  in  this  manner  to  only  a  lim- 
ited extent, 


1'JLS}       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS 


141 


TABLE  13. — CONSUMPTION  AND  EXCRETION  OF  ORGANIC  MATTER 
(Results  expressed  in  pounds  per  period) 


Organic 

Organic 

Ratio  of 

Total 

matter 

Total 

Total 

matter 

Total 

T>0  . 

hay  to 

organic 

con- 

organic 

organic 

con- 

organic 

1  C-^ 

riod 

Weeks 

corn  to 

matter 

sumed 

matter 

matter 

sumed 

matter 

linseed 

con- 

from 

excreted 

con- 

from 

excreted 

meal 

sumed 

clover 

in  feces 

sumed 

clover 

in  feces 

hay 

hay 

Maintenance  Lot 


Steer  650 

Steer  656 

1 

1-5 

1:1:0 

323.03 

157.43 

96.64 

323.01 

157.43 

92.74 

2 

8-13 

1:3:0 

324.18 

79.10 

70.26 

323  .  71 

78.94 

64.96 

3 

17-22 

1:5:0 

303  .  32 

50.06 

61.43 

303.32 

50.06 

60.57 

4 

25-30 

1:4:1 

298.23 

47.76 

54.60 

297.13 

47.76 

60.36 

51 

34-37 

1:4:1 

411.39 

68.68 

97-.77 

184.  57 

31.10 

35.95 

Total3 

1-37 

2205  .  67 

521  .  18 

495  .  98 

1948.44 

479.65 

421.60 

One-Third-Feed  Lot 


1 

2 
3 
4 
54 

1-5 
8-13 
17-22 
25-30 
34-37 

1  :1  :0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

452.75 
519.46 
456.37 
430.14 
447.24 

220.70 
126.66 
75.35 
68.94 
74.48 

135.41 
134.19 
107.70 
89.86 
109.28 

465.84 
541  .  62 
495.24 
464.54 
305  .  33 

227.16 
132.11 
81.73 
74.44 
50.86 

164.44 
148.33 
109.00 
106.05 
64.99 

Total-' 

1-37 

..." 

3162.07 

739.90 

769.24 

3110.33 

749.13 

806.15 

Two-Thirds-Feed  Lot 


1 

2 
3 
4 
5* 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  652J 

Steer  665 

585.09 
711.03 
610.19 
563.02 
109.82 

285  .  19 
173.48 
101  .  57 
90.11 
18.07 

200.69 
207.27 
138.60 
119.01 
23.59 

608.57 
760.92 
692.42 
630.89 
424.08 

296.55 
185.53 
114.43 
101.11 
70.61 

213.65 
230.77 
189.91 
165.11 
111.11 

Total3 

1-37 

3623.24 

896.82 

948.92 

4258.87 

1014.87 

1243.57 

Full-Feed  Lot 


Steer  663: 

Steer  661 

1 

2 
3 
4 
5 

1-5 
8-13 
17-22 
25-30 
34-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1-4:1 

688.39 
818.39 
664.65 
606.73 

333.83 
199.24 
109.40 
97.01 

241.66 
238.27 
164.14 
117.49 

744.71 
962.34 
748  .  97 
797  .  15 
546.16 

363.01 
234.17 
123  .  28 
127.78 
88.43 

277.51 
372.06 
248.92 
205.77 
123.26 

Total3 

1-37 

3651.55 

950.40 

1014.45 

5212.46 

1243.23 

1686.91 

'licmovcd  at  end  of  34th  week.     Removed  at  end  of  30th  week. 

3Includes  transitional  periods. 

4Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 


142 


BULLETIN   No.  209 


[June, 


TABLE  14. — EXCRETION  OP  ORGANIC  MATTER 

(Results  expressed  in  percent  of  total  organic  matter  consumed  and  in  percent  of 
organic  matter  of  hay) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Percent  of 
total 
organic 
matter 
excreted 
in  feces 

Percent  of 
organic 
matter 
of  clover 
hay 
excreted 
in  feces 

Percent  of 
total 
organic 
matter 
excreted 
in  feces 

Percent  of 
organic 
matter 
of  clover 
hay 
excreted 
in  feces 

Maintenance  Lot 

1 

2 
3 
4 

5' 

Totalj 

1-5 
8-13 
17-22 
25-30 
.    34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
.      1:4:1 
1:4:1 

Steer  650 

Steer  656 

29.92 
21.67 
20.25 
18.31 
23.77 

22.49 

61.39 
88.82 
122.71 
114.32 
142.36 

95.16 

28.71 
20.38 
19.97 
20.31 
19.48 

21.64 

58.91 
82.29 
120.99 
126.38 
115.59 

87.90 

One-Third-Feed  Lot 

1 
2 
3 
4 
51 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

29.91 
25.83 
23.60 
20.89 
24.43 

24.33 

61.35 
105.95 
142.93 
130.35 
146.72 

103.97 

35.30 
27.39 
22.01 
22.83 
21.29 

25.92 

72.39 
112.28 
133.37 
142.46 
127.78 

107.61 

Two-Thirds-Feed  Lot 

1 
2 
3 
4 
5* 

Total3 

1-5 

8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  652* 

Steer  665 

34.30 
29.75 
22.71 
21  14 
21.48 

26.19 

70.37 
119.48 
136.46 
132  .  07 
130.55 

105.81 

35.11 
30.33 
27.43 
26.17 
26.20 

29.20 

72.05 
124  .  38 
165  .  96 
163.30 
157.36 

122.53 

Full-Feed  Lot 

1 
2 
3 
4 
5 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  663^ 

Steer  661 

35.11 
29.11 
24.70 
19.36 

72.39 
119.59 
150.04 
121.11 

37.27 
38.66 
33.24 
25.81 
22.57 

32.36 

76.45 
158.88 
201.91 
161.03 
139.39 

135.69 

27.78 

106.74 

Removed  at  end  of  34th  week.     2Bcmovcd  at  end  of  30th  week. 

"Includes  transitional  periods. 

4Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 


1918]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS  143 

TABLE  15. — ORGANIC  MATTER  CONSUMED  FROM  FARM-GROWN  FEEDS  AND  ORGANIC 

MATTER  EXCRETED  IN  THE  FECES 
(Results  expressed  in  pounds  and  in  percent  per  period) 


Period 

Organic 
matter 
consumed 
from  farm- 
grown 
feeds 

Total 
organic 
matter 
excreted 
in  feces 

Percent 
excreted 
in  feces1 

Organic 
matter 
consumed 
from  farm- 
grown 
feeds 

Total 
organic 
matter 
excreted 
in  feces 

Percent 
excreted 
in  feces1 

Maintenance  Lot 


4 
52 

Steer  650 

Steer  656 

Ibs. 
248.57 
341.68 

/6s. 
54.60 
97.77 

percent 
21.97 
28.61 

Ibs. 
247.47 
153.00 

/6s. 
60.36 
35.95 

percent 
24.39 
23.50 

One-Third-Feed  Lot 


4 
52 

Steer  666 

Steer  669 

358.47    • 
371.65 

89.86 
109.28 

25.07 
29.40 

387.15 
253.71 

.    106.05 
64.99 

27.39 
25.62 

Two-Thirds-Feed  Lot 


4 
52 

Steer  652J 

Steer  665 

469.34 
91.48 

119.01 
23.59 

25.36 
25.79 

525  .  78 
352.41 

165.11 
111.11 

31.40 
31.53 

Full-Feed  Lot 


Steer  6634 

Steer  661 

4 
5 

505.88 

117.49 

24.22 

664.31 
456  .  40 

205  .  77 
123.26 

30.97 
27.01 

1This  column  expresses  the  total  organic  matter  excreted   in  percentage  of 
the  organic  matter  consumed  from  the  farm-grown  feeds  of  the  ration. 
2Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 
"Removed  at  end  of  34th  week.    4Removed  at  end  of  30th  week. 


EXCRETION  OF  NITROGEN 

Inasmuch  as  nitrogen  is  one  of  the  essential  fertilizing  elements 
in  which  the  soil  is  often  deficient,  and  as  the  ordinary  farm  ration 
usually  contains  a  considerable  amount  of  this  element,  largely  in 
the  form  of  proteins  and  their  derivatives,  it  is  not  only  of  scientific 
interest  but  also  of  practical  importance  to  study  the  amounts  of 
nitrogen  excreted  by  farm  animals  and  the  manner  in  which  it  is 
excreted. 

All  animals  require  the  element  nitrogen.  However,  an  animal 
cannot  utilize  free  nitrogen  as  it  exists  in  the  air,  nor  nitrogen  in 
inorganic  forms.  As  a  matter  of  fact,  the  animal  organism  utilizes 
nitrogen  only  when  it  is  in  organic  combination  in  the  form  of  com- 
plex substances  known  as  proteins,  and  to  some  extent  in  the  form 
of  the  derivatives  of  the  proteins.  Thus  in  practice  the  proteins  must 
be  supplied  in  the  food.  However,  before  the  food  proteins  can  be 
utilized  by  the  animal  as  a  source  of  nitrogen,  they  must  undergo 
digestion,  a  process  by  which  the  digestive  agents  change  into  forms 
which  are  soluble,  diffusible,  and  available  to  the  tissues,  such  portions 


144  BULLETIN  No.  209  [June, 

of  the  feed  as  are  capable  of  such  changes  in  the  digestive  tract.  Thus 
only  a  part  of  the  nitrogen  of  the  food  is  digested  and  absorbed.  The 
other  part,  including  various  excretory  substances  from  the  body, 
usually  amounts  to  from  25  to  75  percent  of  the  total  nitrogen  of 
the  food,  and  is  excreted  in  the  feces.  The  nitrogen  of  the  feces  may 
be  used  as  plant  food. 

the  animal  organism  requires  a  certain  amount  of  nitrogen  in 
the  form  of  proteins  (or  their  derivatives)  for  the  repair  and  growth 
of  the  protein  tissues  of  the  body.  The  protein  tissues  are  continually 
undergoing  a  breaking-down  process,  with  the  elimination  of  the 
nitrogen  of  the  protein  molecule  thru  the  urine.  This  broken-down 
tissue  must  be  replaced  by  the  digested  proteins  from  the  food.  Also, 
in  the  growing  animal,  there  is  an  actual  increase  in  the  amount  of 
protein  tissue. 

In  the  young  animal  the  demands  of  the  body  for  nitrogen  for 
growth  are  considerable,  while  in  the  older  animal  they  are  quite 
small,  being  reduced  to  practically  nothing  in  the  mature  animal.  In 
the  pregnant  animal,  a  small  amount  of  nitrogen  is  essential  for 
the  development  of  the  fetus,  while  later,  a  considerable  amount  is 
essential  for  milk  production.  After  all  these  demands  of  the  body 
have  been  satisfied,  any  surplus  of  protein  digestion  products  which 
remains  may  be  oxidized  for  the  energy  which  it  contains,  or  it  prob- 
ably may  be  changed  to  fat  and  stored  as  such  in  the  body.  In  either 
case,  the  nitrogen  of  the  protein  digestion  products  is  split  off  and 
is  excreted  in  the  urine.  Thus,  the  urine  contains  nitrogen  from  two 
sources:  viz.,  (1)  from  the  tissue  protein  which  is  broken  down  in 
the  functioning  of  the  body;  and  (2)  from  any  surplus  of  digested 
protein  which  may  remain  after  the  demands  of  the  body  for  nitrogen 
have  been  satisfied.  The  amount  of  nitrogen  from  the  first  source 
is  practically  constant,  while  the  amount  from  the  second  source  may 
be  quite  variable,  depending  especially  upon  the  amount  of  nitrogen 
consumed  by  the  animal. 

Thus  it  is  evident  that  the  amount  of  nitrogen  excreted,  and  the 
manner  by  which  it  is  excreted  by  the  animal  may  be  quite  variable, 
depending  upon  a  number  of  important  f  actors,  among  which  may  be 
enumerated  the  following:  (1)  The  amount  of  protein  in  the  ration; 
of  course  the  more  protein  there  is  in  the  ration,  the  more  nitrogen 
there  will  be  excreted,  other  things  being  equal.  (2)  The  digestibility 
of  the  protein ;  there  will  be  more  nitrogen  excreted  from  a  ration 
containing  less  digestible  feeds,  other  things  being  equal.  (3)  The  age 
of  the  animal ;  an  older  animal  will  require  less  protein  for  growth 
and,  consequently,  there  will  be  a  larger  surplus,  the  nitrogen  of 
which  will  be  excreted.  (4)  The  condition  of  the  animal  as  regards 
pregnancy ;  a  'pregnant  animal  will  utilize  somewhat  more  of  the 
protein  of  the  food,  leaving  less  nitrogen  to  be  excreted.  (5)  The 


1918]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS          145 


condition  of  the  animal  as  regards  milk  production ;  a  milk-producing 
animal  will  utilize  more  of  the  protein  of  the  food,  leaving  less  nitrogen 
to  be  excreted.  Consequently,  in  applying  the  results  of  this  or  any 
similar  experiment  to  other  conditions,  these  factors  should  all  be 
carefully  considered. 

Referring  to  the  data  given  in  Table  17,  it  may  be  seen  that  the 
amounts  of  feeds  consumed  apparently  had  but  little  effect  upon  the 

TABLE  16. — CONSUMPTION  AND  EXCRETION  OF  NITROGEN 
(Results  expressed  in  pounds  per  period) 


Pe- 
riod 

s 

9 

1 

Ratio 
of  hay 
to 
corn 
to 
linseed 
meal 

Total  nitrogen 
consumed 

a  >> 

§.e 

O-G 

a.S 
8- 

Eg 

—  -  - 

£  % 

Nitrogen  excreted 

Total  nitrogen 
consumed 

11 

c  5 

0) 
MT3 
O    OJ 

•-  s 

i^t    03 

Nitrogen  excreted 

In 

feces 

In 
urine 

Total 

In 

feces 

In 
urine 

Total 

1 

2 
3 
4 

5' 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Maintenance  Lot 

Steer  650 

Steer  656 

6.10 
5.20 
4.60 
7.25 
10.24 

44.10 

3.81 
1.73 
1.02 
0.93 
1.40 

11.04 

3.45 
2.66 
2.21 
2.15 
3.35 

18.05 

1.68 
1.90 
1.76 
4.25 
4.96 

19.51 

5.13 

4.57 
3.98 
6.40 
8.31 

37.56 

6.10 
5.20 
4.60 
7.25 
4.63 

37.72 

3.81 
1.73 
1.02 
0.93 
0.63 

10.16 

3.03 
2.51 
2.21 
2.25 
1.44 

15  .  35 

1.95 
2.00 
1.70 
4.52 
3.11 

18.13 

4.98 
4.52 
3.92 
6.77 
4.56 

33.48 

1 
2 
3 
4 
51 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1  5:0 
1:4:1 
1:4:1 

One-Third-Feed  Lot 

Steer  666 

Steer  669 

8.55 
8.33 
6.92 
10.41 
11.10 

60.99 

5.35 
2.78 
1.53 
1.34 
1.52 

15.68 

4.42 
4.03 
3.27 
3.48 
4.03 

25.65 

2.16 
3.28 
2  87 
5.29 
6.38 

27.24 

6.58 
7.31 
6.14 
8.77 
10.41 

52.89 

8.80 
8.69 
7.51 
11.30 

7.58 

60.03 

5.50 
2.90 
1.66 
1.44 
1.03 

15.87 

4.91 
4.03 
3.39 
3.66 
2.26 

24.63 

2.46 
3.32 
3.31 
6.80 
4.86 

28.69 

7.37 
7.34 
6.70 
10.46 
7.12 

53.33 

1 

2 
3 
4 

54 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Two-Thirds-Feed  Lot 

Steer  6521 

Steer  665 

11.05 
11.42 
9.32 
13.67 
2.73 

68.40 

6.91 
3.80 
2.06 
1.75 
0.37 

19.00 

6.45 
5.87 
4.72 
4.54 
0.84 

30.93 

2.66 
3.85 
3.41 
7.55 
1.68 

28.44 

9.10 
9.72 
8.13 
12.09 
2.52 

59  37 

11.49 
12.20 
10.49 
15.34 
10.53 

82.10 

7.18 
4.07 
2.33 
1.96 
1.44 

21.50 

6.68 
6.00 
5.21 
5.29 
3.65 

56.71 

2.76 
4.06 
3.99 
8.52 
6.50 

35.57 

9.44 
10.06 
9.20 
13.82 
10.15 

72.28 

1 

2 
3 
4 
5 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Full-Feed  Lot 

Steer  663* 

Steer  661 

12.96 
13.16 
10.07 
14.61 

8.09 
4.37 
2.22 
1.88 

7.46 
7.09 
4.84 
4.28 

2.91 
4.61 
3.42 
9.70 

10.37 
11.69 
8.26 
13.98 

14.15 
15.43 
11.29 
19.39 
13.31 

101.07 

8.79 
5.13 
2.51 
2.48 
1.80 

26.34 

8.62 
8.89 
5.89 
6.72 
4.31 

47.01 

3.22 
4.78 
3.89 
10.18 
7.93 

41.49 

11.84 
13.67 
9.78 
16.89 
12.24 

88.50 

65.73 

20.14 

30.97 

26.44 

57.41 

'Removed  at  end  of  34th  week.      2Removed  at  end  of  30th  week. 

'Includes  transitional  periods. 

"Stoois  fi~>0,  fififi,  and  (552  were  on  full  fee«l  in  this  period. 


146 


BULLETIN  No.  209 


percentage  of  nitrogen  excreted.  In  fact,  the  nitrogen  excretions 
of  all  eight  steers,  with  only  a  few  exceptions,  showed  little  variation 
during  a  given  period.  Also,  there  were  only  slight  variations  when 
the  entire  thirty-seven  weeks  of  the  experiment  are  considered.  Con- 
sequently, it  seems  justifiable  to  take  an  average  of  the  results  of 
the  eight  steers  as  representing  the  percentage  of  nitrogen  excreted 
during  each  period.  From  these  results  ( Table  27 )  it  is  apparent  that 

TABLE  17. — EXCRETION  OF  NITROGEN 

(Results  expressed  in  percent  of  total  nitrogen  consumed,  and  in  percent  of 
nitrogen  of  hay) 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

In  percent 
of  total 
nitrogen 

In  percent 
of  nitrogen 
of  clover 
hay 

In  percent 
of  total 
nitrogen 

In  percent 
of  nitrogen 
of  clover 
hay 

Maintenance  Lot 

1 
2 
3 
4 
54 

Total5 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  650 

Steer  656 

84.10 
87.77 
86.68 
88.22 
81.21 

85.18 

134.65 
264.16 
390.20 

688.17 
593  .  57 

340.22 

81.56 
87.07 
85.25 
93.35 
98.32 

88.77 

130.71 
261.27 
384.31 
727.96 
723.81 

329.53 

One-Third-Feed  Lot 

1 

2 
3 
4 
54 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

76.95 
87.69 
88.73 
84.28 
93.81 

86.72 

122.99 
262.95 
401.31 
654.48 
684.87 

337.31 

83.74 
84.60 
89.45 
92.58 
93.93 

88.84 

134.00 
253.10 
403.61 
.      726.39 
691.26 

336.04 

Two-Thirds-Feed  Lot 

1 
2 
3 

4 
54 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6521 

Steer  665 

82.39 
85.13 
87.19 
88.45 
92.31 

86.80 

131.69 
255.79 
394  .  66 
690.86 
681.08 

312.47 

82.11 
82.50 
87.71 
90.06 
96.41 

88.03 

131.48 
247.17 
394.85 
705.10 
704.86 

336.19 

Full-Feed  Lot 

1 

2 
3 
4 
5 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0   . 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  663* 

Steer  661 

80.02 
88.83 
82.06 
95.68 

128.18 
267.51 
372.07 
743.62 

83.67 
.     88.61 
86.66 
87.14 
91.94 

87.56 

134.70 
266.47 
389.64 
681  .  05 
680.00 

332.19 

87.34 

285.05 

Removed  at  end  of  34th  week.     2Rernoved  at  end  of  30th  week. 

'Includes  transitional  periods. 

4Steers  650,  666,  and  C52  were  on  full  feed  in  this  period. 


1918]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS          147 

the  total  excretory  nitrogen  (urine  and  feces)  made  up  82  percent 
of  the  total  nitrogen  consumed  in  Period  1;  87  percent,  in  Period  2; 
87  percent,  in  Period  3 ;  90  percent,  in.  Period  4 ;  93  percent,  in  Period 
5 ;  and  8  7  percent  for  the  entire  experiment  of  thirty-seven  weeks. 

In  an  experiment  with  six  mature  milch  cows  at  this  station,1 
80.32  percent  of  the  nitrogen  consumed  was  excreted  in  the  feces  and 
urine,  and  20.12  percent  was  excreted  in  the  milk.  In  an  experiment 
with  two  milch  cows  at  the  Pennsylvania  Station,2  84.64  percent  of  the 
nitrogen  appeared  in  the  feces  and  urine  and  16.76  percent  in  the  milk. 
Warington:5  calculates  from  experiments  by  Lawes  and  Gilbert  at  the 
Rothamsted  Station  that  in  the  case  of  a  mature  fat  steer  96  percent 
of  the  nitrogen  of  the  ration  was  excreted.  A  milch  cow  excreted 
75  percent  of  the  nitrogen  in  the  manure,  while  a  calf  excreted  only 
31  percent.  Thus  the  results  of  our  own  experiment  do  not  differ 
materially  from  the  results  of  other  investigations  with  cattle,  except 
in  the  case  of  the  milch  cow  of  Lawes  and  Gilbert.  It  is  of  interest 
to  note  that  the  addition  of  nitrogen  in  the  form  of  linseed  meal  to  the 
ration  in  Periods  4  and  5  caused  not  only  an  increase  in  the  absolute 
.amounts  of  nitrogen  excreted  but  also  an  increase  in  the  percentage 
of  nitrogen  excreted. 

Inasmuch  as  the  nitrogen  is  excreted  in  both  the  feces  and  the 
urine,  it  is  of  interest  and  practical  value  to  note  what  proportion  of 
the  total  amount  excreted  is  in  each.  Apparently  the  amount  of  feed 
consumed  had  little  or  no  influence  upon  the  way  the  nitrogen 
was  excreted,  i.  e.,  whether  it  was  in  the  feces  or  in  the  urine  (Table 
18) .  The  averages  of  these  results  (Table  19)  show  the  distribution  of 
the  nitrogen  excreted  to  have  been  in  Period  1,  68.5  percent  in  the 
feces  and  31.5  percent  in  the  urine;  in  Period  2,  59  percent  in  the 
feces  and  41  percent  in  the  urine ;  in  Period  3,  56  percent  in  the  feces 
and  44  percent  in  the  urine ;  in  Period  4,  36  percent  in  the  feces  and 
64  percent  in  the  urine;  in  Period  5,  35  percent  in  the  feces  and  65 
percent  in  the  urine;  and  in  the  entire  experiment  of  thirty-seven 
weeks,  50  percent  in  the  feces  and  50  percent  in  the  urine. 

In  the  Illinois  experiment  with  milch  cows  already  noted,  44 
percent  of  the  nitrogen  excreted  in  the  manures  was  in  the  feces 
and  56  percent  in  the  urine.  In  the  Pennsylvania  experiment  with 
milch  cows,  37  percent  of  the  nitrogen  was  in  the  feces  and  63  percent 
in  the  urine.  According  to  Van  Slyke,4  49  percent  of  the  nitrogen 
is  excreted  in  the  feces  and  51  percent  in  the  urine,  in  the  case  of  cattle. 

From  these  figures  it  is  evident  that  a  large  percentage  of  the 
nitrogen  excreted  is  in  the  urine.  Thus  it  is  important  to  conserve  the 

Hopkins:     Soil  Fertility  and  Permanent  Agriculture,  p.  201. 
;Penn.  Agr.  Exp.  Sta.  Ann.  Ept.  1899-1900,  p.  321. 
'Chemistry  of  the  Farm,  p.  214. 
••Fertilizers  and  Crops,  p.  295. 


148 


BULLETIN  No.  209 


[June, 


urine  of  our  farm  animals  by  using  plenty  of  bedding,  water-tight 
stalls  and  barnyards,  and  by  other  suitable  means.  If  the  urine  in 
this  experiment  had  been  wasted,  from  one- third  to  two-thirds  of 
the  nitrogen  of  the  manure  would  have  been  lost.  Incidentally,  ac- 
cording to  Van  Slyke,  85  percent  of  the  potassium  (potash)  excreted 
is  in  the  urine  and  15  percent  in  the  feces,  in  the  case  of  cattle.  Inas- 
much as  the  fertilizing  ingredients  of  the  liquid  excrement  are  on  the 
whole  more  available  for  plant  growth  than  those  of  the  solid  excre- 
ment, and  inasmuch  as  nitrogen  and  potassium  are  expensive  fer- 
tilizing elements  and  occur  in  manure  in  large  amounts,  it>  is  evident 
that  at  least  half  the  fertilizing  value  of  cattle  manure  is  in  the  urine. 

TABLE  18. — EXCRETION  OP  NITROGEN 
(Results  expressed  in  percent  of  total  nitrogen  excreted) 


Pe- 
riod 

WeeKs 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

In 

feces 

In 
urine 

In 

feces 

In 

urine 

In 

feces 

In 
urine 

Maintenance  Lot 

Steer  650 

Steer-  656 

Average 

1 

2 
o 
4 
5 
Aver 
age3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

67.25 
58.21 
55.53 
33  .  59 
40.31 

48.06 

32.75 
41  79 
44.47 
66.41 
59.69 

51.94 

60.84 
55.53 
56.38 
33.23 
31.58 

45.85 

39.16 
44.47 
43.62 
66.77 
68.42 

54.15 

64.05 
56.87 
55.95 
33.41 
35.94 

46.95 

35.95 
43.13 
44.05 
66.59 
64.06 

53.05 

One-Third-Feed  Lot 

1 
2 
3 
4 
5 
Aver- 
age3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1  :1  :0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

Average 

67.17 
55.13 
53.26 
39.68 
38.71 

48.50 

32.82 
44.87 
46.74 
60.32 
61.29 

51.50 

66.62 
54.90 
50.60 
34.99 
31.74 

46.18 

33.38 
45.10 
49.40 
65.01 
68.26 

53.82 

66.89 
55.01 
51.93 
37.33 
35.22 

47.34 

33.11 

44.99 
48.07 
62.67 
64.78 

52.66 

Two-Thirds-Feed  Lot 

1 
2 
3 
4 
5 
Aver- 
age3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1.0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  652* 

Steer  665 

Average 

70.88 
60.39 
58.06 
37.55 
33.33 

52.10 

29.12 
39.61 
41.94 
62.45 
66.67 

47.90 

70.76 
59.64 
56.63 
38.28 
35.96 

50.79 

29.24 
40.36 
43.37 
61.72 
64.04 

49.21 

70.82 
60.01 
57.34 
37.91 
34.64 

51.44 

29.18 
39.99 
42.66 
62.09 
65.30 

48.56 

Full-Feed  Lot 

1 
2 
3 
4' 
5 
Aver- 
age3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6632 

Steer  661 

Average 

71.94 
60.65 
58.60 
30.62 

53.95 

28.06 
39.35 
41  .  40 
69.38 

46.05 

72.80 
65.03 
60.22 
39.79 
35.21 

53.12 

27.20 
34.97 
39.78 
60.21 
64.79 

46.88 

72.37 
62.84 
59.41 
35.20 
35.21 

53.53 

27.63 
37.16 
40.59 
64.80 
64.79 

46.47 

'Removed  at  end  of  «54th  week. 
'Includes  transitional  periods. 


-Removed  at  end  of  30th  \\cek. 


J')1S]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD 


TABLE  19. — AVERAGE  EXCRETION  OF  NITROGEN  BY  ALL  STEERS 
(Results  expressed  in  percent  of  total  nitrogen  excreted) 


Period 

Weeks 

Ratio  of  hay 
to  corn  to 
linseed  meal 

In  feces 

In  urine 

1 
2 
3 
4 
5 

Average  

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3.0 
1:5*) 
1:4:1  • 
1:4:1 

68.53 
58.68 
56.16 
35.96 
35.25 

49.82 

31.47 
41.32 
43.84 
64.04 
64.75 

50.18 

The  data  given  in  Table  20  show  that  in  Periods  4  and  5  the 
amount  of  the  ration  consumed  had  no  apparent  influence  upon  the 
percentage  of  nitrogen  excreted.  Also  the  data  show  that  123  to  177, 
or  an  average  of  160,  percent  as  much  nitrogen  was  excreted  in  the 
manure  as  was  consumed  in  the  farm-grown  feeds.  In  other  words, 
when  the  ration  consisted  of  clover  hay,  ground  corn,  and  linseed 
meal  in  the  proportions  of  1  to  4  to  1,  1.6  pounds  ,of  nitrogen  were 
excreted  in  the  manure  for  every  pound  of  nitrogen  removed  from 
the  soil  (or  air)  by  the  hay  and  corn  of  the  ration.  Altho  some  of 

TABLE  20. — NITROGEN  CONSUMED  FROM   FARM-GROWN   FEEDS  AND  TOTAL 

NITROGEN  EXCRETED 
(Results  expressed  in  pounds  and  in  percent  per  period) 


Nitrogen 

Nitrogen 

Period 

consumed 
from  farm- 
grown 

Total 
nitrogen 
excreted 

Percent 
excreted1 

consumed 
from  farm- 
grown 

Total 
nitrogen 
excreted 

Percent 
excreted1 

feeds 

feeds 

Maintenance  Lot 


4 
& 

Steer  650 

Steer  656 

Ibs. 
4.01 
5.69 

Ibs. 
6.40 
8.31 

percent 
159.60 
146.05 

Ibs. 
4.01 
2.57 

Ibs. 
6.77 
4.56 

percent 
168.83 
177.43 

One-Third-Feed  Lot 


4 

5* 

Steer  666 

Steer  669 

5.74 
6.17 

4.67 
4.93 

122.91 
125.15 

6  25 
4.19 

10.46 
7.12 

167.36 
169.93 

Two-Thirds-Feed  Lot 

4 

Steer  6523 

Steer  665 

7.56 
1.53 

12.09 
2.52 

159.92 
164.70 

8.49 
•    5.86 

13.82 
10.15 

162.78 
173.21 

Full-Feed  Lot 

4 
5 

Steer  6634 

Steer  661 

8.03 

13.98 

174.10 

10.73 

7.46 

16.89 
12.24 

157.41 
164.08 

'This    column    expresses    the    total    nitrogen    excreted    in    percentage    of   the 
nitrogen  consumed  from  the  farm-grown  feeds  of  the  ration. 
^Steers  650,  G66,  and  652  were  on  full  feed  in  this  period. 
3Eemoved  at  end  of  34th  week. 
4Ecmoved  at  end  of  30th  week. 


150  BULLETIN  No.  209  [June, 

the  nitrogen  of  the  manure  undoubtedly  would  be  lost  even  under 
optimum  conditions  (probably  10  to  15  percent),  still,  if  reasonable 
care  were  exercised  in  the  conservation  of  the  manure,  the  quantity 
of  nitrogen  returned  to  the  soil  in  the  manure  would  be  equal  to  and 
probably  exceed  the  nitrogen  removed  by  the  clover  hay  and  the  corn, 
especially  is  this  seen  to  be  true  when,  one  considers  the  amount  of 
nitrogen  added  to  the  soil  by  the  roots  and  stubble  of  the  clover  plants. 
In  this  connection  it  should  be  noted  that  in  case  nitrogenous  by- 
products were  for  any  reason  unavailable,  it  obviously  would  be  im- 
possible to  maintain  the  fertility  by  this  method  alone. 

It  is  also  of  interest  to  compare  the  amount  of  nitrogen  which 
was  returned  in  the  form  of  manure,  with  the  amount  which  would 
have  been  returned  by  a  system  of  farming  in  which  the  corn  is  sold 
and  the  clover  is  plowed  under.  Referring  again  to  Table  17,  it  is 
seen  that  in  all  the  periods  of  this  experiment  more  nitrogen  was  re- 
turned in  the  manure  than  was  contained  in  the  clover  hay  fed.  An 
average  of  the  results  for  the  eight  steers  shows  that  in  Period  1, 
131.05  percent  as  much  nitrogen  was  returned  in  the  manure  as  would 
have  been  returnee,  by  plowing  under  the  clover;  in  Period  2,  259.80 
percent;  in  Period  3,  391.33  percent;  in  Period  4,  702.20  percent;  in 
Period  5,  679.92  percent ;  and  for  the  entire  experiment,  326.12  percent. 
The  large  increase'  in  Periods  4  and  5  is  due  to  the  addition  of  the 
nitrogenous  concentrate  (linseed  meal)  to  the  ration. 

It  has  already  been  noted  on  page  140  that  in  rotations  where  two 
crops  of  corn  are  secured  in  four  or  five  years,  corn  and  clover  hay 
are  produced  in  a  proportion  not  greatly  different  from  that  in  which 
these  feeds  were  used  in  Periods  1  and  2.  In  a  three-year  rotation 
the  proportions  of  corn  and  clover  are  approximately  the  same  as  fed 
in  Period  1.  Thus  it  is  apparent  that  when  corn  and  clover  hay  are  fed 
in  approximately  the  same  proportions  in  which  they  should  be  pro- 
duced in  a  good  corn-belt  rotation,  considerably  more  nitrogen  can  be 
returned  to  the  soil  than  under  the  other  system  of  farming  assumed 
immediately  above.  As  previously  explained  (page  140)  the  results 
in  Periods  3,  4,  and  5  are  of  practical  value  only  in  case  the  feeder 
feeds  a  part  of  his  clover  to  other  stock  or  purchases  corn  additional 
to  that  produced  on  the  farm. 

EXCRETION  OF  PHOSPHORUS 

Inasmuch  as  phosphorus  is  the  key  to  permanent  systems  of 
agriculture,  in  a  large  part  of  the  corn  belt  at  least,  the  excretion  of 
phosphorus  should  be  of  considerable  interest  to  the  practical  farmer 
as  well  as  to  the  scientific  investigator. 

As  already  stated,  practically  all  of  the  phosphorus  excreted 
by  the  animals  used  in  this  study  was  in  the  feces,  only  small  amounts 
being  found  in  the  urine,  except  in  the  case  of  Steer  656,  whose  urine 


1918}       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS          151 

contained  twenty  times  as  much  phosphorus  as  the  urine  of  some  of 
the  other  steers.  In  the  Illinois  and  Pennsylvania  experiments  with 
milch  cows  previously  quoted,  only  very  small  amounts  of  phosphorus 
were  excreted  in  the  urine.  According  to  Van  Slyke,1  the  cow  and 
horse  excrete  practically  all  the  phosphorus  in  the  feces.  In  the  case 
of  the  hog,  12  percent  of  the  excreted  phosphorus  is  in  the  urine,  while 
in  the  case  of  the  sheep  5  percent  is  in  the  urine.  Why  Steer  656  was  an 
exception  to  the  general  rule,  we  are  unable  to  explain. 

It  is  seen  from  the  data  given  in  Table  22  that  the  amount  of 
feed  consumed  apparently  had  no  effect  upon  the  percentage  of  the 
phosphorus  of  the  total  ration  that  was  excreted.  However,  it  will 
be  noted  that  there  is  considerably  more  variation  between  the  steers 
in  the  same  period  than  in  the  case  of  the  nitrogen  excreted.  The 
percentage  of  phosphorus  excreted  by  Steer  656  is  considerably  lower 
than  that  excreted  by  the  other  steers,  owing  to  the  fact  already  noted, 
that  this  steer  excreted  considerable  phosphorus  in  his  urine.  If  the 
phosphorus  excreted  in  the  feces  in  Periods  1  and  2  is  added  to  the 
amounts  of  phosphorus  excreted  in  the  urine  in  these  periods  (see 
Tables  9  and  12) ,  and  then  the  percentage  of  total  phosphorus  excreted 
calculated,  it  is  found  that  in  Period  1,  87.79  percent,  and  in  Period 
2,  84.94  percent  of  the  total  phosphorus  consumed  was  excreted.  These 
results  are  not  essentially  different  from  the  results  from  the  other 
steers  during  these  periods.  It  is  possible  that  the  variations  among 
the  other  steers  would  be  lessened  if  accurate  determinations  of  the 
amounts  of  phosphorus  in  the  urine  were  available  and  included  in 
the  amounts  of  phosphorus  excreted. 

Table  27  shows  the  average  percentage  of  phosphorus  excreted  by 
all  the  steers  excepting  Steer  656,  which  has  been  omitted  for  obvious 
reasons.  From  these  data  it  is  seen  that  of  the  total  amount  of  phos- 
phorus excreted,  practically  all  was  in  the  feces,  and  that  the  quan- 
tity of  feed  consumed  had  no  influence  upon  the  percentage  of  phos- 
phorus excreted.  In  Period  1,  93  percent  of  the  total  phosphorus  con- 
sumed was  excreted ;  in  Period  2,  96  percent ;  in  Period  3,  85  percent ; 
in.  Period  4,  81  percent;  in  Period  5,  81  percent;  and  in  the  entire 
experiment,  87  percent. 

In  the  experiment  at  this  station  with  four  milch  cows,  already 
mentioned,  about  73  percent  of  the  phosphorus  of  the  ration  was 
excreted  in  the  manures  and  about  22  percent  in  the  milk.  In  the 
Pennsylvania  experiment  with  two  milch  cows,  about  71  percent  of 
the  phosphorus  of  the  ration  was  excreted  in  the  manures  and  about 
21  percent  in  the  milk.  One  would  naturally  expect  that  milch  cows 
would  excrete  in  the  manures  a  smaller  proportion  of  the  phosphorus 
of  their  rations  than  two-year-old  steers. 

Table  23  shows  the  amounts  of  phosphorus  consumed  from  the 
farm-grown  feeds  (i.e.,  the  corn  and  clover  hay)  ;  the  amounts  of 
fertilizers  and  Crops,  p.  295. 


152 


BULLETIN  No.  209 


[June, 


phosphorus  excreted  from  the  total  ration  (i.e.,  the  clover  hay,  corn, 
and  linseed  meal)  ;  and  the  phosphorus  excreted  from  the  total  ration 
expressed  in  the  percentage  of  the  phosphorus  consumed  from  the 
farm-grown  feeds  of  the  ration. 

The  results  pertaining  to  Steer  656  need  not  be  considered,  owing 
to  the  fact,  already  explained,  that  he  excreted  a  large  but  undeter- 
mined part  of  the  phosphorus  in  the  urine,  while  the  other  steers 
excreted  the  phosphorus  largely  thru  the  feces.  As  in  the  case  of 
the  organic  matter  and  the  nitrogen,  so  with  the  phosphorus,  the 

TABLE  21. — CONSUMPTION  AND  EXCRETION  OP  PHOSPHORUS 
(Results  expressed  in  pounds  per  period) 


Period 

Weeks 

Ratio  of 

hay  to 
corn  to 
linseed 
meal 

Total 
phos- 
phorus 
con- 
sumed 

Phos- 
phorus 
con- 
sumed 
in  hay 

Phos- 
phorus 
excreted 
in 
feces 

Total 
phos- 
phorus 
con- 
sumed 

Phos- 
phorus 
con- 
sumed 
in  hay 

Phos- 
phorus 
excreted 
in 
feces 

Maintenance  Lot 

1 

2 
3 

4 
54 

Tota3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  650      • 

Steer  656 

0.868 
0.871 
0.890 
1.188 
1.678 

7.309 

0.358 
0.156 
0.081 
0.077 
0.127 

0.960 

0.794 
0.860 
0.799 
0.966 
1.319 

6.245 

0.868 
0.870 
0.890 
1.188 
0.759 

6.265 

0.358 
0.156 
0.081 
0.077 
0.057 

0.883 

0.632 
0.477 
0.325 
0.357 
0.229 

2.686 

One-Third-Feed  Lot 

1 

2 
3 
4 

5* 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

1.216 
1.396 
1.341 
1.725 
1.820 

10.149 

0.502 
0.250 
0.122 
0.111 
0.137 

1.363 

0.988 
1.331 
1.191 
1.367 
1.638 

8.921 

1.251 
1.456 
1.456 
1.852 
1.243 

10.009 

0.517 
0.261 
0.132 
0.120 
0.094 

1.380 

1.119 
1.321 
1.340 
1.707 
1.088 

9.065 

Two-Thirds-Feed  Lot 

1 
2 
3 

4 
54 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6521 

Steer  665 

1.583 
1.913 
1.808 
2.240 
0.417 

11.385 

0.649 
0.342 
0.165 
0.145 
0  033 

1.652 

1.581 
1.774 
1.277 
1.409 
0.255 

8.843 

1.635 
2.016 
2.036 
2.514 
1.726 

13.718 

0.675 
0.366 
0.185 
0.163 
0.130 

1.869 

1.528 
1.965 
1.916 
2.216 
1.504 

12.507 

Full-Feed  Lot 

1 
2 
3 
4 
5 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  663* 

Steer.  661 

1.856 
2.209 
1.954 
2.392 

0.760 
0.393 
0.177 
0.156 

1.732 
2.072 
1.366 
2.011 

1.994 
2.584 
2.190 
3.178 
2.182 

16.794 

0.826 
0.462 
0.200 
0.206 
0.163 

2.290 

2.005 
2.668 
1.951 
2.427 
1.758 

14.616 

11.024 

1.750 

9.457 

'Removed  at  end  of  34th  week.    2Removed  at  end  of  30th  week. 

'Includes  transitional  periods. 

'Steers  650,  6GO,  and  652  were  on  full  feed  in  this  period. 


1918}       FERTILIZING  CONSTITUENTS  EXCRETED  UY  Two  YEAR-OLD  STEERS 


153 


percentages  excreted  in  Periods  4  and  5  apparently  were  not  influ- 
enced by  the  amounts  of  feed  consumed.  It  is  also  seen  that  during 
these  periods,  when  the  ration  consisted  of  clover  hay,  ground  corn, 
and  linseed  meal  in  the  proportions  of  1  to  4  to  1,  there  was  excreted 
in  the  manure  110  to  160  percent  as  much  phosphorus  as  was  consumed 
in  the  farm-grown  feeds.  In  other  words,  an  average  of  1.4  pounds  of 
phosphorus  was  excreted  in  the  manure  (principally  in  the  feces) 

TABLE  22.— EXCRETION  OF  PHOSPHORUS 

(Results  expressed  in  percent  of  total  phosphorus  consumed,  and  in  percent  of 

phosphorus  of  hay) 


Period 

1 
Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

In  percent 
of  total 
phos- 
phorus 

In  percent 
of  phos- 
phorus 
of  clover 
hay 

In  percent 
of  total 
phos- 
phorus 

In  percent 
of  phos- 
phorus 
of  clover 
hay 

Maintenance  Lot 

1 
2 
3 
4 
5' 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  650 

Steer  656 

91.48 
98.76 
89.79 
81.29 
78.60 

85.45 

221.79 
551.28 
986.42 
1254.55 
1038.58 

650.52 

72.81 
54.82 
36.54 
30.02 
30.13 

42.87 

176.54 
305.77 
401  .  23 
463.64 
401.75 

304.19 

One-Third-Feed  Lot 

1 
2 
3 

4 
5* 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1  :1  :0  . 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  666 

Steer  669 

81.25 
95.34 
88.87 
79.28 
89.98 

87.89 

196.81 
532  .  40 
976.23 
1231.53 
1195.62 

654.51 

89.42 
90.79 
92.09 
92.21 
87.50 

90.57 

216'.  44 
506.13 
1015.15 
1422.50 
1157.45 

656.88 

Two-Thirds-Feed  Lot 

1 
2 
3 
4 
5 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  6521 

Steer  665 

99.89 
92.72 
70.61 
62.89 
61.15 

77.67 

243.61 
518.71 
773  .94 
971  .  72 
772.73 

535.29 

93.44 
96.00 
94.10 
88.12 
87.12 

91.17 

226.37 
536.89 
1035.68 
1359.51 
1156.92 

669.18 

Full-Feed  Lot 

1 
2 
3 
4 
5 

Total3 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer  663- 

Steer  661 

93.34 
93.80 
69.91 
84.09 

227  .  89 
527  .  23 
771.75 
1289.10 

100.55 
103  .  24 
89.07 
76.36 
80.57 

87.03 

242  .  73 
577.49 
975.50 
1178.16 
1078.53 

638.25 

85.79' 

540.40 

Removed  at  end  of  34th  week.     ^Removed  at  end  of  30th  week. 

'Includes  transitional  periods. 

4Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 


154 


BULLETIN   ]STu.   liO'J 


[June, 


for  every  pound  of  phosphorus  removed  from  the  soil  by  the  hay  and 
corn  that  were  fed.  It  is  true  with  phosphorus,  as  with  nitrogen,  that 
some  of  it  may  be  lost  before  the  manure  is  put  on  the  soil ;  but  if  the 
manure  is  properly  cared  for,  most  of  the  element  can  be  returned. 
Under  conditions  such  as  prevailed  during  Periods  4  and  5  of  this 
experiment,  the  phosphorus  content  of  the  soil  would  not  only  be 
maintained  but  it  probably  would  be  increased. 

It  is  also  of  interest  to  compare  the  amount  of  phosphorus  re- 
turned to  the  farm  when  the  corn  and  clover  are  fed  to  two-year-old 
beef  cattle,  with  the  amount  returned  when  the  corn  is  sold  and  the 
clover  is  plowed  under  for  manure.  From  Table  22  it  is  seen  that 
considerably  more  phosphorus  was  excreted  in  the  manure  than  would 
have  been  returned  to  the  farm  had  the  clover  been  plowed  under. 
An  average  of  the  results  for  the  eight  steers  shows  that  in  Period 
1,  225.09  percent  as  much  phosphorus  was  returned  in  the  manure 
as  was  in  the  clover  hay  consumed;  in  Period  2,  550.02  percent;  in 
Period  3,  933.52  percent;  in  Period  4,  1,243.87  percent;  in  Period  5, 
1,066.64  percent;  and  in  the  entire  experiment,  620.72  percent.  It 
seems  safe  to  conclude,  therefore,  that  much  more  phosphorus  can 

TABLE  23. — PHOSPHORUS  CONSUMED  FROM  FARM-GROWN  FEEDS  AND  TOTAL 

PHOSPHORUS  EXCRETED 
(Results  expressed  in  pounds  and  in  percent  per  period) 


Period 

Phos- 
phorus 
consumed 
in  farm 
feeds 

Total 
phos- 
phorus 
excreted 

Percent 
excreted1 

Phos- 
phorus 
consumed 
.  in  farm 
feeds 

Total 
.  phos- 
phorus 
excreted 

Percent 
excreted1 

Maintenance  Lot 


Steer  650 

Steer  656 

4 

Ibs. 
0.682 

Ibs. 
0.966 

percent 
141.64 

Ibs. 
0.682 

/6s. 
0.357 

percent 

5* 

0.968 

1.319 

136  26 

0.437 

0.229 

One-Third-Feed  Lot 


4 
5* 

Steer  666 

Steer  669 

0.995 
1.050 

1.367 
1.638 

137.39 
156.00 

1.064 
0.717 

1.707 
1.088 

160.43 
151.74 

Two-Thirds-Feed  Lot 


4 

5'2 

Steer  6523 

Steer  665 

1.286 
0.230 

1.409 
0.255 

109.56 
110.87 

1.443 
•  0.996 

2.216 
1.504 

153.57 
151.00 

Full-Feed  Lot 


Steer  6634 

Steer  661 

4 
5 

1.365 

2.011 

147.33 

1.825 
1.268 

2.427 

1.758 

132  .  99 
138.64 

aThis  column  expresses  the  total  phosphorus  excreted  in  percentage  of  the 
phosphorus  consumed  from  the  farm-grown  feeds  of  the  ration. 
-'Steers  650,  666,  and  652  were  on  full  feed  in  this  period, 
"Kemoved  at  end  of  34th  week. 
4Kemoved  at  end  of  30th  week. 


±918'\       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS 


155 


be  returned  to  the  farm  by  feeding  the  crops  to  two-year-old  beef 
cattle  than  can  be  returned  in  a  system  of  farming  in  which  the  corn 
is  sold  and  the  clover  plowed  under. 

Even  in  Periods  1  and  2,  when  corn  and  clover  hay  were  fed  in 
approximately  the  same  proportions  as  they  are  grown  in  a  good 
rotation,  it  would  have  been  possible  to  return  to  the  soil  relatively 
much  more  phosphorus  than  could  have  been  returned  by  the  other 
system  of  farming  assumed  above. 

FINANCIAL  STATEMENT 

It  is  of  interest  to  calculate  the  value  of  the  fertilizing  elements 
of  the  manure  on  the  basis  of  their  cost  in  commercial  fertilizers. 
Accordingly,  we  have  assumed  the  following  prices:  for  nitrogen  15 
cents ;  for  phosphorus  10  cents ;  and  for  potassium  6  cents  per  pound ; 
which  values  are  approximately  the  average  market  prices  of  these 
fertilizing  elements  under  ordinary  conditions.  Unfortunately,  the 
consumption  and  excretion  of  potassium  was  not  determined.  How- 
ever, assuming  the  average  potassium  content  of  clover  hay,  corn,  and 
linseed  meal,  and  assuming  further  that  90  percent  of  the  potassium 
consumed  was  excreted,  it  is  possible  to  calculate  the  approximate 
amounts  of  potassium  in  the  manure. 

TABLE  24. — COMMERCIAL  VALUE  OF  THE  NITROGEN.  PHOSPHORUS,  AND  POTASSIUM 

EXCRETED  PER  PERIODI 


Period 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance  Lot 

One-Third-Feed  Lot 

Steer 
650 

Steer 
656 

Steer 
666 

Steer 
669 

1 
2 
3 
4 
<? 

Total 

1-5 

•      8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

$1.06 
0.92 
0.78 
1.19 
1.56 

$7.24' 

$1.02 
0.87 
0.72 
1.19 
0.78 

$6.  17 

$1.38 
1,45 
1.20 
1.64 
1.92 

$10.21 

$1.52 
1.46 
1.31 
1.94 
1.31 

$10.29 

Two-Thirds-Feed.  Lot 

Full-Feed  Lot 

i 

2 
3 

4 
52 

Total 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

Steer 
6528 

Steer 
•       665 

Steer 
6634 

Steer 
661 

$1.90 
1.94 
1.56 
2.19 
0.46 

$11.41 

$1.96 
2.03 
1.81 
2.56 
1.85 

$14.98 

$2.17 
2.30 
1.61 
2.57 

$11.20 

$2.37 
2.72 
1.93 
3.11 
2.25 

$15.97 

irThis  table  is  based  upon  the  assumption  that  nitrogen  costs  15  cents,  phos- 
phorus 10  cents,  and  potassium  6  cents  per  pound  if  purchased  in  commercial  fer- 
tilizers. 

2Steers  650,  666,  and  652  were  on  full  feed  in  this  period. 

"Removed  at  end  of  34th  week.    'Removed  at  end  of  30th  week. 


156 


BULLETIN  No.  209 


\June, 


The  total  commercial  value  of  the  fertilizing  elements  as  shown 
in  Table  24,  has  been  calculated  by  using  the  amounts  of  nitrogen 
actually  excreted  (  see  Table  16),  the  amounts  of  phosphorus  actually 
excreted  (see  Table  21),  and  the  calculated  amounts  of  potassium 
excreted,  together  with  the  respective  prices  of  the  elements  stated 
above! 

An  inspection  of  these  data  shows  that  the  fertilizing  elements 
in  the  manure  of  Steers  650  and  656  of  the  maintenance  lot,  for. the 
entire  thirty-seven  weeks,  would  have  cost  $7.24  and  $6.17,  respec- 
tively, if  they  had  been  purchased  in  the  form  of  commercial  fertiliz- 
ers ;  of  Steers  666  and  669  of  the  one-third-feed  lot,  $10.21  and  $10.29, 
respectively;  of  Steers  652  and  665  of  the  two-thirds-feed  lot, 
$11.41  and  $14.98,  respectively;  and  of  Steers  663  and  661  of  the  full- 
feed  lot,  $11.20  and  $15.97,  respectively.  The  individual  farmer  must 
not  assume  that  these  fertilizing  elements  will  necessarily  have  these 
values,  as  these  will  depend  largely  upon  the  requirements  of  his  soil 
and  his  system  of  crop  production.  However,  these  figures  do  show 
conclusively  that  the  fertilizing  value  of  the  manure  from  fattening 
steers  is  no  small  item  and  should  be  considered  in  the  balance  sheet 
showing  the  profit  or  loss  of  feeding  operations. 

Table  25  shows  the  same  values  as  those  in  Table  24,  calculated 
per  week.  From  this  table  it  is  seen  that  the  value  of  the  manure 
varied  directly  with  the  amount  of  the  ration  consumed;  that  the 

TABLE  25. — COMMERCIAL  VALUE  OF  THE  NITROGEN,  PHOSPHORUS,  AND  POTASSIUM 

EXCRETED  PER  WEEK1 


Pe- 
riod 

Weeks 

Ratio  of 
hay  to 
corn  to 
linseed 
meal 

Maintenance  Lot 

One-Third-Feed  Lot 

Steer 
650 

Steer 
656 

Aver- 
age 

Steer 
666 

Steer 
669 

Aver- 
.     age 

1 
2 
3 
4 
52 
Aver- 
age 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

$0.21 
0.15 
0.13 
0.20 
0.39 

$0.20 

$0.20 
0.15 
0.12 
0.20 
0.19 

$0.17 

$0.20 
0.15 
0.12 
0.20 
0.29 

$0.18 

$0.28 
0.24 
0.20 
0.27 
0.48 

$0.28 

$0.30 
0.24 
0.22 
0.32 
0.33 

$0.28 

$0.29 
0.24 
0.21 
0.30 
0.40 

$0.28 

Two-Thrrds-Feed  Lot 

Full-Feed  Lot 

Steer 
652 

Steer 
665 

Aver- 
age 

Steer 
663 

Steer 
661 

Aver- 
age 

1 
2 
3 
4 
S2 
Aver- 
age 

1-5 
8-13 
17-22 
25-30 
34-37 

1-37 

1:1:0 
1:3:0 
1:5:0 
1:4:1 
1:4:1 

$0.38 
0.32 
0.26 
0.36 
0.46 

$0.34 

$0.39 
0.34 
0.30 
0.43 
0.46 

$0.40 

$0.38 
0.33 
0.28 
0.40 
0.46 

$0.37 

$0.43 
0.38 
0.27 
0.43 

$0.37 

$0.47 
0.45 
0.32 
0.52 
0.56 

$0.43 

$0.45 
0.41 
0.29 
0.47 
0.56 

$0.40 

1This  table  is  based  upon  the  assumption  that  nitrogen  costs  15  cents,  phos- 
phorus, 10  cents,  and  potassium,  6  cents  per  pound  if  purchased  in  commercial 
fertilizers. 

•"Steers  650,  G6G,  and  652  were  on  full  feed  in  this  period. 


1918]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS  157 

presenee  of  a  considerable  amount  of  clover  hay  in  the  ration  increased 
the  value  of  the  manure,  while  the  presence  of  a  large  proportion  of 
corn  decreased  the  value  of  the  manure ;  and  that  the  addition  of  lin- 
seed meal  to  the  ration  increased  the  value  of  the  manure.  In  Period  1, 
when  the  ration  consisted  of  clover  hay  and  ground  corn  in  equal 
parts,  the  fertilizing  elements  in  the  manure  of  the  maintenance 
steers  would  have  cost  20  cents ;  of  the  one-third-feed  steers,  29  cents ; 


TABLE  26. — COST  OF  FEEDS  CONSUMED  COMPARED  WITH  COMMERCIAL 

MANURE  ExcRETED1 


VALUE  OP 


Ratio 

Value  of 

Value  of 

Pe- 
riod 

Weeks 

of  hay 
to  corn 
to  lin- 
seed 

Value 
of 
feed 

Value 
of 
manure 

manure 
in  per- 
cent of 
value 

Value 
of 
feed 

Value 
of 
manure 

manure 
in  per- 
cent of 
value 

meal 

•  of  feed 

of  feed 

Maintenance  Lot 

Steer  650 

Steer  656 

1 

1-5 

1:1:0 

$2.89 

$1.06 

36.68 

$2.89 

$1.02 

35  .  29 

2 

8-13 

1:3:0 

3.35 

0.92 

27..  46 

3.35 

•  0.87 

25.97 

3 

17-22 

1:5:0 

3.23 

0.78 

24.15 

3.23 

0.72 

22.29 

4 

25-30 

1:4:1 

3.78 

1.19 

31.48 

3.79 

1.19 

31.40 

5 

34-37 

1:4:1 

5.31 

1.56 

29.38 

2.40 

0.78 

32.50 

Total 

1-37 

$24.75 

$7.24 

29.25 

$21.45 

$6.17. 

28.76 

One-Third-Feed  Lot 

Steer  666 

Steer  669 

1 

1-5 

1:1:0 

$4.05 

$1.38 

34.07 

$4.17 

$1.52 

36.45 

2 

8-13 

1:3:0 

5.37 

1.45 

27.00 

5.60 

1.46 

26.07 

3 

17-22 

1:5:0 

4.87 

1.20 

24.64 

5.28 

1.31 

24.81 

4 

25-30 

1:4:1 

5.46 

1.64 

30.04 

5.90 

1.94 

32.88 

5 

34-37 

1:4:1 

5.76 

1.92 

33.33 

3.93 

1.31 

33.33 

Total 

1-37 

$34.55 

$10.21 

29  .  55 

$34.29 

$10.29 

30.01 

Two-Thirds-Feed  Lot 

Steer  652 

Steer  665 

1 

1-5 

1:1:0 

$5.23 

$1.90 

36.33 

$5.44 

$1.96 

36.03 

2 

8-13 

1:3:0 

7.35 

1.94 

26:39 

7.87 

2.03 

25.79 

3 

17-22 

1:5:0 

6.56 

1.56 

23.78 

7.39 

1.81 

24.49 

4 

25-30 

1:4:1 

7.14 

2.19 

30.67 

8.01 

2.56 

31.96 

5 

34-37 

1:4:1 

1.40 

0.46 

32.86 

5.46 

1.85 

33.88 

Total 

1-37 

$39.43 

$11.41 

28.94 

$47.03 

$14.98 

31.85 

Full-Feed  Lot 

Steer  663 

Steer  661 

1 

1-5 

1:1:0 

$6.  13 

$2.17 

35.40 

$6.66 

$2.37 

35.58 

2 

8-13 

1:3:0 

8.45 

2.30 

27  .  22 

9.93 

2.72 

27.39 

3 

17-22 

1:5:0 

7.07 

1.61 

22.77 

7.97 

1.93 

24.22 

4 

25-30 

1:4:1 

7.68 

2.57 

33.46 

10.12 

3.11 

30.73 

5 

34-37 

1:4:1 

6  84 

2  25 

32  89 

Total 

1-37 

$38.65 

$11.20 

28.98 

$57.45 

$15.97 

27.79 

1Corn  valued  at  56  cents  per  bushel,  hay  at  $10  per  ton,  linseed  meal  at  $40 
per  ton,  nitrogen  at  15  cents  per  pound,  phosphorus  at  10  cents  per  pound,  and 
potassium  at  t>  cents  per  pound. 


158  BULLETIN   No.   209  [June, 

of  the  two-thirds-feed  steers,  38  cents;  and  of  the  full-feed  steeis, 
45  cents  per  head  per  week.  In  Period  2,  when  the  ration  con- 
sisted of  one  part  of  clover  hay  and  three  parts  of  ground  corn, 
the  fertilizing  elements  in  the  manure  of  the  maintenance  steers 
would  have  cost  15  cents;  of  the  one-third-feed  steers,  24  cents;  of 
the  two-thirds-feed  steers,  33  cents;  and  of  the  full-feed  steers,  41  cents 
per  head  per  week.  In  Period  3,  when  the  ration  consisted  of  one 
part  of  clover  hay  and  five  parts  of  ground  corn,  the  fertilizing  ele- 
ments in  the  manure  of  the  maintenance  steers  would  have  cost  12  cents ; 
of  the  one-third-feed  steers,  21  cents ;  of  the  two-thirds-feed  steers, 
28  cents;  and  of  the  full-feed  steers,  29  cents,  per  head  per  week. 
In  Period  4,  when  the  ration  consisted  of  one  part  of  clover  hay,  four 
parts  of  corn,  and  one  part  of  linseed  meal,  the  fertilizing  elements  in 
the  manure  of  the  maintenance  steers  would  have  cost  20  cents ;  of  the 
one-third-feed  steers,  30  cents ;  of  the  two-thirds-feed  steers,  40  cents ; 
and  of  the  full-feed  steers,  47  cents  per  head  per  week.  In  Period  5, 
on  the  same  ration  as  in  Period  4,  the  fertilizing  elements  in  the 
manure  from -Steer  650  (on  full  feed)  would  have  cost  39  cents;  of 
Steer  656  (on  maintenance),  19  cents;  of  Steer  666  (on  full  feed), 
48  cents;  of  Steer  669  (on  one-third  feed),  33  cents;  of  Steer  652  (011 
full  feed),  46  cents;  of  Steer  665  (on  two-thirds  feed),  46  cents;  and 
of  Steer  ^61  (on  full  feed),  56  cents  per  week.  In  this  connection,  it 
should  be  noted  that  these  figures  do  not  include  the  values  of  the 
organic  matter  of  the  manures. 

These  figures  will  give  the  stock-feeder  some  idea,  at  least,  as 
to  the  value  of  the  manure  produced  by  two-year-old  steers  under 
similar  conditions. 

It  is  also  of  interest  to  compare  the  commercial  value  of  the 
manure  produced  by  the  two-year-old  steers  with  the  cost  of  the  feed 
consumed.  Table  26  has  been  calculated  upon  this  basis,  corn  being 
valued  at  56  cents  a  bushel,  clover  hay  at  $10  per  ton,  linseed  meal  at 
$40  per  ton,  nitrogen  at  15  cents  per  pound,  phosphorus  at  10  cents 
per  pound,  and  potassium  at  6  cents  per  pound.  While  these  valu- 
ations do  not  represent  the  market  prices  of  either  the  feeds  used  or 
of  the  fertilizing  elements  at  the  time  of  the  publication  of  this  bul- 
letin, yet  they  are  comparable  with  each  other  and  represent  average 
prices  under  ordinary  conditions. 

It  is  clear  from  the  data  in  Table  26  that  no  inconsiderable  part  of 
the  cost  of  the  feed  is  returned  in  the  manure.  In.  Period  1,  the  com- 
mercial value  of  the  manure  represented  35.77  percent  of  the  cost 
of  the  feed  consumed;  in  Period  2,  26.66  percent;  in  Period  3,  23.89 
percent ;  in  Period  4,  31.58  percent ;  in  Period  5,  28.52  percent ;  and 
during  the  entire  experiment,  29.39  percent.  Of  course,  this  does 
not  take  into  consideration  any  losses  in  handling  the  manure  from 
the  time  it  is  excreted  until  it  is  applied  to  the  soil.  While  these  losses 


1018\       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAR-OLD  STEERS          159 

may  be  considerable,  yet  such  is  not  necessarily  the  case.  On  the 
other  hand,  these  figures  do  not  assign  any  value  to  the  organic  matter 
of  the  manure.  It  is  possible,  or  even  probable,  that  the  value  of  the 
organic  matter  would  more  than  offset  the  losses  of  nitrogen,  phos- 
phorus, and  potassium  in  handling  the  manure.  In  any  case,  the  fact 
remains  that  the  manure  does  have  a  considerable  value  which  is  not 
often  taken  into  consideration  in  figuring  the  financial  balance  in 
cattle-feeding  operations. 

SUMMARY 

1.  Eight  two-year-old,  choice  feeder  steers  were  divided  into  four 
lots  of  two  steers  each.    One  lot  was  given  a  ration  slightly  above  main- 
tenance ;  another,  as  much  feed  as  the  steers  would  eat  readily ;  another, 
an  amount  of  feed  equal  to  the  maintenance  ration  plus  one-third 
of  the  difference  between  the  maintenance  and  the  full-feed  ration; 
and  another,  an  amount  equal  to  the  maintenance  ration  plus  two- 
thirds  of  the  difference  between  the  maintenance  and  the  full-feed 
ration. 

2.  The  experiment  lasted  for  thirty-seven  weeks  and  was  divided 
into  five  test  periods.     The  first  period  was  five  weeks  in  length,  the 
second,  third,  and  fourth  were  each  six  weeks  in  length,  and  the  fifth 
was  four  weeks  in  length. 

3.  The  feeds  used  were  clover  hay,  ground  corn,  and  linseed  oil 
meal.    The  ration  of  the  first  test  period  consisted  of  clover  hay  and 
ground  corn  in  the  ratio  of  1  to  1 ;  that  of  the  second,  of  clover  hay 
and  ground  corn  in  the  ratio  of  1  to  3  ;  that  of  the  third,  of  clover  hay 
and  ground  corn  in  the  ratio  of  1  to  5 ;  and  that  of  the  fourth  and 
fifth,  of  clover  hay,  ground  corn,  and  linseed  oil  meal  in  the  ratio 
of  1  to  4  to  1. 

4.  The  consumption  of  organic  matter,  nitrogen,  and  phosphorus, 
the  excretion  of  organic  matter  in  the  f  eces,  the  excretion  of  nitrogen 

TABLE  27. — SUMMARY  OF  THE  AVERAGE  EXCRETION  OF  ORGANIC  MATTER,  NITRO- 
GEN, AND  PHOSPHORUS 
(Results  expressed  in  percent  of  the  amount  consumed) 


Ratio  of 

Period 

Weeks 

hay  to 
corn  to 
linseed 

Organic 
matter 
in  feces 

Nitrogen 
in  feces 
and  urine 

Phosphorus 
in  feces1 

meal 

1 

1-5 

1:1:0 

33.20 

81.82 

92.77 

2 

8-13 

1:3:0 

27.89 

86.53 

95.81 

3 

17-22 

1:5:0 

24.24 

86.72 

84.92 

4 

25-30 

1:4:1 

21.85 

89.97 

80.61 

5 

34-37 

1:4:1 

22.75 

92.56 

80.82 

Total  

1-37 

26.24 

87.40 

86.51 

Emitting  Steer  656. 


160  BULLETOX  No.   209  [June, 

in  the  feces  and  urine,  and  the  excretion  of  phosphorus  in  the  feces 
and  in  the  urine  (for  thirteen  weeks  only)  were  determined. 

5.  In  Period  1,  on  a  ration  consisting  of  clover  hay  and  ground 
corn  in  equal  parts,  33  percent  of  the  organic  matter  was  recovered  in 
the  manure;  in  Period  2,  on  a  ration  consisting  of  1  part  clover  hay 
and  3  parts  ground  corn,  28  percent  was  recovered ;  in  Period  3,  when 
the  ration  consisted  of  1  part  clover  hay  and  5  parts  ground  corn,  24 

.percent  was  recovered;  in  Periods  4  and  5,  when  the  ration  consisted 
of  1  part  clover  hay,  4  parts  ground  corn,  and  1  part  linseed  meal, 
22  percent  and  23  percent,  respectively,  were  recovered;  during  the 
entire  experiment  of  thirty-seven  weeks,  26  percent  was  recovered. 

6.  The  amount  of  feed  consumed  had  no  influence  upon  the 
percentage  of  organic  matter  excreted,  except  in  Period  1,  and  possibly 
in  Period  2. 

7.  Slightly  more  organic  matter  was  recovered  in  the  manure 
than  would  have  been  recovered  in  a  system  of  farming  in  which  the 
corn  is  sold  and  the  clover  plowed  under. 

8.  In  Period  1,  82  percent  of  the  nitrogen  consumed  was  ex- 
creted, 69  percent  of  it  being  in  the  feces  and  31  percent  in  the  urine ; 
in  Period  2,  87  percent  was  excreted,  59  percent  in  the  feces  and  41 
percent  in  the  urine ;  in  Period  3,  87  percent  was  excreted,  56  percent 
in  the  feces  and  44  percent  in  the  urine ;  in  Period  4,  90  percent  was 
excreted,  36  percent  in  the  feces  and  64  percent  in  the  urine ;  in 
Period  5,  93  percent  was  excreted,  35  percent  in  the  feces  and  65 
percent  in  the  urine;  during  the  entire  experiment  of  thirty-seven 
weeks,  87  percent  was  excreted,  50  percent  in  the  feces  and  50  percent 
in  the  urine. 

9.  The  amount  of  feed  consumed  had  no  influence  upon  the 
percentage  of  nitrogen  excreted. 

10.  When  linseed  meal  was  introduced  into  the  ration,  the  nitro- 
gen balance  of  the  soil  was  more  than  maintained,  160  percent  as  much 
nitrogen  being  excreted  as  was  contained  in  the  farm-grown  feeds. 

11.  The  nitrogen  recovered  in  the  manure  averaged  326  percent 
of  that  which  would  have  been  recovered  in  a  system  of  farming  in 
which  the  corn  is  sold  and  the  clover  plowed  under.    In  Period  1,  the 
proportion  was  131  percent;  in  Period  2,  260  percent;  in  Period  3, 
391  percent ;  in  Period  4,  702  percent ;  in  Period  5,  680  percent. 

12.  In  Period  1,  93  percent  of  the  phosphorus  consumed  was 
excreted ;  in  Period  2,  96  percent ;  in  Period  3,  85  percent ;  in  Period 
4,  81  percent ;  in  Period  5,  81  percent ;  and  during  the  entire  experi- 
ment, 87  percent.    Practically  all  of  the  excreted  phosphorus  was  in  the 
feces,  except  in  the  case  of  one  steer. 

13.  The  amount  of  feed  consumed  had  no  influence  upon  the 
percentage  of  phosphorus  excreted. 

14.  When  linseed  meal  was  introduced  into  the  ration,  the  phos- 
phorus balance  of  the  soil  was  more  than  maintained,  141  percent  as 


1918]       FERTILIZING  CONSTITUENTS  EXCRETED  BY  TWO-YEAK-OLD  STEERS 


161 


much,  phosphorus  being  excreted  as  was  contained  in  the  farm-grown 
feeds. 

15.  The  phosphorus  recovered  in  the  manure  averaged  521  per- 
cent of  that  which  would  have  been  recovered  in  a  system  of  farming 
in  which  the  corn  is  sold  and  the  clover  plowed  under.    In  Period  1, 
the  proportion  was  225  percent;  in  Period  2,  550  percent;  in  Period 
3,  934  percent;  in  Period  4,  1,244  percent;  and  in  Period  5,  1,067 
percent. 

16.  Assuming  that  nitrogen  costs  15  cents  per  pound,  phosphorus 
10  cents,  and  potassium  6  cents,  if  purchased  in  commercial  fertilizers, 
the  values  of  these  elements  excreted  per  head  per  week  were  as  fol- 
lows: 


Period 

Maintenance 
lot 

Ohe-third- 
feed  lot 

Two-thirds- 
feed  lot 

Full-feed 
lot 

1 

$0.20 

$0.29 

$0.38 

$0.45 

2 

0.15 

0.24 

0.33 

0.41 

3 

0.12 

0.21 

0.28 

0.29 

4 

0.20 

0.30 

0.40 

0.47 

5 

0.29 

0.40 

0.46 

0.56 

Total 

$0.18 

$0.28 

$0.37 

$0.40 

17.  The  value  of  the  manure  varied  directly  with  the  amount 
of  feed  consumed.     It  also  varied  with  the  character  of  the  ration, 
being  greater  the  larger  the  proportion  of  clover  hay  in  the  ration, 
and  greatest  when  linseed  oil  meal  was  introduced  into  the  ration. 

18.  At  the  values  assumed  for  fertilizing  elements,  no  incon- 
siderable part  of  the  cost  of  the  feed  was  returned  in  the  manure. 
In  Period  1,  the  commercial  value  of  the  manure  was  36  percent  of  the 
cost  of  the  feed;  in  Period  2,  27  percent;  in  Period  3,  24  percent;  in 
Period  4;  32  percent ;  in  Period  5,  29  percent ;  and  in  the  entire  experi- 
ment, 29  percent. 

CONCLUSIONS 

1.  By  feeding  two-year-old  steers  on  clover  hay  and  corn,  and 
carefully  conserving  the  resulting  manure,  it  is  possible  to  return  to 
the  soil  one-fourth  to  one-third  of  the  organic  matter  of  the  ration  and 
three-fourths  to  four-fifths  of  the  nitrogen  and  phosphorous  of  the 
ration. 

2.  It  is  possible  to  maintain,  or  even  to  increase,  the  nitrogen 
and  phosphorus  content  of  the  soil  by  adding  to  the  ration  a  nitrog- 
enous supplement  such  as  linseed  or  cottonseed  meal. 

3.  When  a  three-year  rotation  is  practiced  (e.  g.,  corn,  oats,  and 
clover),  approximately  two-thirds  as  much  organic  matter  can  be  re- 
turned to  the  land  by  feeding  two-year-old  cattle  and  returning  the 


162  BULLETIN  No.  209 

manure  to  the  soil  as  can  be  returned  in  a  system  of  farming  in  which 
the  corn  is  sold  and  the  clover  plowed  under.  In  a  four-  or  five-year 
rotation,  corn  appearing  twice  (e.  g.,  corn,  corn,  oats,  and  clover;  or 
corn,  corn,  oats,  clover,  and  wheat),  as  much  organic  matter  can  be 
returned  by  feeding  the  corn  and  clover  as  by  selling  the  corn  and 
plowing  under  the  clover. 

4.  In  the  three-year  rotation  above  mentioned,  slightly  more 
nitrogen  can  be  returned  by  feeding  the  corn  and  clover  than  by  sell- 
ing the  corn  and  plowing  under  the  clover.    In  the  four-  and  five-year 
rotations,  about  twice  as  much  nitrogen  can  be  returned. 

5.  In  the  three-year  rotation,  approximately  twice  as  much  phos- 
phorus can  be  returned  by  feeding  the  corn  and  clover  as  by  selling 
the  corn  and  plowing  under  the  clover.    In  the  four-  and  five-year  rota- 
tions, four  or  five  times  as  much  can  be  returned. 


The  authors  wish  to  acknowledge  the  efficient  assistance  rendered 
by  J.  J.  Yoke  and  W.  H.  Balis  in  the  feeding,  weighing,  and  care  of 
the  animals;  by  F.  W.  Gill  in  the  analytical  work;  and  by  P.  A. 
Hoffman,  W.  J.  Gage,  Jr.,  and  W.  A.  Hixson  in  the  weighing  and 
sampling  of  the  feeds,  orts,  f eces,  and  urine  and  in  the  keeping  of  many 
of  the  records. 


UNIVERSITY  OF  ILLINOIS-URBANA 


